I recently purchased one of these. I got the i5 version. Here are my thoughts.
I was looking for a small great looking somewhat powerful PC for my living room. I wanted to use it for games and HTPC.
Looks
The unit is sexy. It is not obnoxious looking like most Alienware hardware. It is matte black and has a small foot print. The adjustable LED's are great. They can be toggled to just about any color or can be completely shut off.You can customize colors to change when ever you launch a game. I was playing Xcom and the game automatically changed the colors to blue. Cool!
Interface
I dumped Windows 8 after about a day of it keeping me from doing what I wanted. It just gets in the way of how I want to interface with my PC. So that meant dumping the AlienUI. For the short time I played with the AlienUI, it was OK. All could be controlled with the provided Xbox 360 controller. It is essentially another user profile that launches Steam in Big Picture mode. I don't miss it.
I should note Alpha runs Windows 7 just fine. The only driver that didn't work from Dell's site was for the NIC. I ended up downloading one from Broadcom and it works. In addition, the LED control app had to be extracted and then I could launch the Setup.exe. I have not tried installing the latest AlienUI on Windows 7. Steam runs just as well as all the others (Uplay, Origin).
Performance
The unit itself has a decent amount of horsepower with the exception of the HD. The first thing I did was replace it. 5400RPM was too slow. I would have went with a 500GB SSD but opted for a 750GB 7200RPM due to cost. Games install and load adequately on the new drive. On paper it should match if not exceed the power of a PS4/Xbone. I chose the i5 4590T model with 8GB of RAM. Performance wise, the video card is apparently somewhere in between a Nvidia 860m and a 750ti. Dell/Alienware isn't saying exactly what it is officially. They just call it a custom built GPU with 2GB GDDR5 memory.
I wanted to replace my unused PS4 with something I would play more often. So I was hoping that the Alpha really could go toe to toe with the PS4 when it came to game settings. The first game I loaded up was Witcher 3. I was disappointed when I fired up Geforce Experience and it recommend 1600x900 with everything on low. I ended up using the guide over at Eurogamer to set the graphics options as close to what a next gen console could do. I was hitting 30fps @1080p for the most part but it would dip to the mid 20's in large towns especially when there were multiple light sources. I think the PS4 drops pretty low and often too. I dropped the shadows to low and a few other settings to low and was able to keep a consistent 30fps with most settings at med-high. I wanted a better experience so my final settings were a little higher although with a lowered resolution of 1600x900. I can't really tell the difference between 1080p or 900p from 14ft away on my 60" TV. What I could tell was smoother gameplay as I was hitting high 30's to mid 40's on my FPS.
I fired up other games like Batman Arkham Origins, Metro 2033, Skyrim, Fallout, Crysis 3. I could run all of those games at 1080p with mostly high/ultra settings. I would hit 45-60 FPS depending on the game. I used MSI Afterburner to overclock the video card and get an additional 5-6 FPS from most games.
Netflix, HBOGo, iTunes and all other streaming or media runs just fine on this. I watch a lot of YouTube and having a keyboard and mouse (Logitech K400) is way better than using a controller to navigate YouTube.
Overall impressions
I paid about $750.00. It came with some free games on Steam. Free two day shipping. I used the Dell Preferred account and got $70.00 back in Dell credit. Dell made a mistake on shipping so I called in. And for my troubles they sent out the Alienware TactX keyboard and mouse combo for free! I definitely got good value for my money.
The Alpha is a great piece of hardware. It is easy to upgrade minus the video card. And that is what concerns me. Again, on paper this little unit should give the next gen consoles a run. But with no options to upgrade the GPU, I fear it will be left behind in the graphics department. PS4 and Xbone games can be optimized to take full advantage of the consoles they are running on. It should be theoretically possible to mimic the settings on most games, but in reality it just doesn't happen often.
The good thing is with the Alpha is it is a PC and you have options. With sliders and changes to resolution, at the end of the day you can find the settings that suit your needs thus enjoy gaming, PC gaming.
I'd be happy to answer any questions on the Alpha. So ask away.