I picked it up on sale last weekend and got my poorly skill optimized martial arts assassin into Act 4 at level 25. I completely forgot about the once per difficulty re-skill and burned it early on at like level 10 and that slowed me down a bit. When I re-spec in nightmare things will pick up more but my gear is also mostly shit but finding the upgrades and inching towards more power is still super fun. I only had to run countess twice to get my Stealth runes so that is the best thing I have. I do have one decent rare claw that I found as well. The building charges and unleashing them is a lot of fun.
For me one of the most frustrating things about it, and maybe because I'm a filthy casual playing with a controller now is that it is so easy to get hung up on the environment and in the tight corridors trying to get through doors. I constantly have my map overlay up as well.
The game does show it's age but from the tons of hours I played in high school both original and LoD, it's still pretty excellent too.
They did a really good job with the graphical update. It runs worse on my computer than Diablo 4 beta did but my PC is old as shit (i5 2500k o/c'd to 4.4, GTX 960 2 GB, 24 GB PC 1333)
Really enjoying my time with an old glowed-up friend