I'm thinking I could probably go ahead and write up what I remember of the demo. I played it on saturday so it's not incredibly vivid (or at least I don't think so?).
I like foraging for items and consider myself a completionist (to masochistic levels-- 100%'d way too many games that didn't really need to be 100%'d). So I scrounged as thoroughly as I could and it was actually quite tense to do so when there were enemies around.
The first clicker, the "tutorial" one in the demo, kind of gave me that feel since I looked around the room for items before proceeding on. I could have killed it but knew I could just bypass it which I did. The actual distraction mechanics are quite enjoyable to use.
It's not too long before I got to the actual first combat scenario, described in that reddit post, and I feel I approached the combat quite differently than a lot of my friends described to me. I've heard a lot of people attempt to "stealth kill" everything which is possible but it seems way too difficult to pull off effectively especially since there were a lot of enemies in a fairly small space (4 runners and that single clicker). There were 3 runners grouped fairly close together in the center of the area (between 2 walls), the fourth on its own, and the clicker farther back towards the exit. I could stealth kill the runner fairly easily. You can either choke them out which takes longer and seems to make some amount of noise or shiv them with a knife that can make. Every shiv or use seems to "use up" the knife and it has 3 'charges' on it. You can restrengthen in through the crafting system like any other weapon (there is a degradation system of sorts like I mentioned with the knife's charges). Shiv seems to be much faster and a lot quieter but it's hard to tell.
I'll try to quickly describe the layout. There is this long hallway that opens into all three "rooms". I was in the room farthest to the right. The exit and the clicker is the room on the left, and the group of three runners are in the middle. The wall is torn down partially in the area opposite the hallway so you can run (and see) between all three rooms from within them as well.
Now then, I shiv the lone runner in the right room, I can somewhat make out the runners in the middle room and they're making there way in the hallway (and the clicker is just bumbling around in the left room). I ended up being quite aggressive. I had 8 rounds for my pistol (maybe it was 6) and 2 in a revolver I picked up earlier. I didn't open fire immediately, though, when I saw the first runner enter the hallway. So I rushed and intercepted it, engaged it in a fist fight. This alerted the other two which were nearby and I knew the clicker would be approaching fairly soon. It didn't take me too long to take out the first runner. The other two runners were now all over me and the clicker was (probably) right on me. I didn't see it but I could hear it. However, I remembered earlier in the loading screen for the demo that you can "break" from a fight with L2 and rush out of a crowd. I made sure to do that and I sprinted back in the right room and all the way around to the left room using the space left by the torn down walls. The clicker was gone and in the hallway since I didn't run into it and the runners were directly behind me. I climbed up on a cement ramp (looked like part of a ceiling had fallen down and made a platform to climb on to). I turned around and saw the two runners and whipped out of my pistol.
Now, when I was watching the demo in line it looked like the players were awful shots but when I finally got to point my gun at the runners and lining up the shot it was a lot more awkward than I thought it would be. It definitely feels like there is no aim assist at all (or very little). The runners were climbing up the incline at this point and I used that time to aim the first shot. Bam. First runner down. Second runner was mostly up on the incline now and propping itself up. I hear the clicker going crazy off in the distance. I line up my pistol. Bam. Miss. He's still up and starting to barrel toward me now. I fire again but hit his chest and he stumbles for a second and continues running. I stop aiming and run at him and smash him against the wall and he stumbles to the ground. I pull out my gun again and it centers on his head and I fire and he's down. The clicking sound is very loud at this point and I look to my right and the thing is in the room with me (down on the lower level). I aim my pistol go for a headshot. Miss. Decide it isn't worth the effort so I feel like just using a few rounds in the chest will be fine. I fire 2 or 3 more in its chest and it's just stumbling around but it's definitely not down. I believe I was out of ammo for my pistol at this point so I switch to my revolver with 2 shots left and hope to god it takes it out. One shot to the head. It doesn't go down. I fire quickly again and this time it collapses and I'm fucking glad it does. I go over the bodies and only find one spare bullet for my pistol.
However, I grabbed a bat by the clicker and upgraded my shiv. I move on quickly remembering I wanted to finish the demo (being told it was difficult, knowing it was after the first death, and yearning for that sense of accomplishment). The actual traversal is pretty linear, at least in this section. Lots of cinematic camera work and neat environments but nothing complex here to navigate. I actually end up getting stuck in this underground subway station entrance which has collapsed on itself. I'm getting irritated and know I'm losing time (they only give you 30 minutes to finish the whole thing) so I'm rushing myself. Finally I find where I'm supposed to go and annoyed that I missed it the first time.
Moving on I start to hear clicking. The room ahead of me is very large and there's lots of chest-high walls I can see over. However I can't see much and I don't use the hearing vision to scope it out (I probably forgot it at that moment). I go in my inventory and I'm decked out from having scavenged so much so I end up making 3 molotovs. I throw one molotov into the room. It lights up and a clicker goes crazy and runs right into the fire due to the noise. I see 3, maybe 4 runners bumble towards the fire and I chuck the other two at them. They all crumple and die from the blaze. It's dead silent now. I don't hear anything so I move forward and grab the shotgun right at the opening of the room. I move around the left and hear a bit of gargling but it's pitch dark so I can't make out much aside from the chest high wall to my right and a lot of darkness in the center of the room (plus the fire from the molotovs and the 4-5 burning bodies). I prep my shotgun and inch forward. I have had my flashlight off the entire time demo since I didn't want to expose myself to any of the runners and didn't want to turn it on now. I get around a corner and a runner is right there in my face. I pull the trigger out of gut reaction and fire too far to the left to take it down in one shot and have to use a second. A clicker far off starts screaming and I tense up horribly. I have one shell left in the shotgun and one left in the pistol and I can hardly see a damn thing. I'm crouched down and inching forward at a snail's pace and hope to god there isn't more than just one clicker. At this point I use the hearing vision and can't see anything at all. I feel like people complaining about it don't realize how small the radius really is or feels while you're playing. But I don't see a damn thing. The clicking is horrendously loud at this point though and I know it's around. I see light coming over a wall and I peak over and see a lone clicker standing far off by a garage door of sorts. At this point I know a shotgun blast in the face is the only way to take it out and I run quickly forward a bit. A scream filled my ears and I hear its footsteps get closer. I look to my left and I see Ellie ducked behind the wall the light was shining over. I crawl back over to it and I see the clicker directly over me. I know this is my one shot and I feel the sweat in my hands. I pop my head up over the cover, point the barrel right in its face, and fire.
The room is dead silent now. Ellie says its all clear and I feel so god damn glad right then. I run over to where the light was coming through. They called "five minutes to go" about five minutes ago and I rush forward looking for the end of the demo but it keeps going. Lots of traversal through the streets and I see where I'm supposed to go just as they call time. I ended up finishing the demo about thirty seconds after they called time and was very sad I didn't get a cheap little brick as a prize (I didn't care much for the brick but I wanted a sign of accomplishment which I did not get).
I'll quickly mention I only died once in the demo and it was in the first encounter. Both times I took out all four runners but on the first time I left the clicker alive and I started moving a large desk that made a lot of noise. I figured it would attract the clicker so I looked around and didn't see it approaching (though I could hear it). I proceeded to move the desk again but then the screen went black and reloaded the checkpoint (I heard the clicker again but no animation played of the neck bite so it just threw me off). Was a bit bummed out at the first death and in retrospect wished I could've beat the whole thing without a single one.
Now as far as impressions go, I felt this sealed my desire to purchase the game. The combat is where this game shines and boy was it as tense as I hoped it would be. Fighting the zombies is horrifying even when I feel the AI isn't what makes it gold. The actual human combat still is somewhat unexperienced (I saw a live playthrough at PAX Prime but would like to see it for myself) so it's hard to say how the human AI feels, but the zombie combat is sufficiently horrifying and I would like to see how it plays out when you deal with both.
Nonetheless, I've been set on buying this game for a while now and this demo experience simply sealed the deal for me. I'm incredibly excited.
edit: Didn't realized I wrote so much; I'm pretty sure this is incredibly ramble-y, sorry for any incoherency and feel free to ask questions (I seem to remember it more vividly than I thought).