Completed this last night with all side missions done, absolutely adored it. They nailed pretty much everything that made the original great, from the look, the audio design, the atmosphere and the general pace of the game, plus the quite visceral and tense combat, then expanded on everything even more. There are so many ways it could have gone wrong but this was a real love letter to the original game. Even small things like being able to turn off the DS2-style button prompts on doors/item boxes for a bit of added immersion shows the developers are huge fans of the original. I'll still love the original but this has largely surpassed it for me.
It wasn't absolutely perfect; the voice acting was often a bit naff, I didn't mind Isaac talking but Hammond often sounded like the script was being read for the first time. Enemies were sometimes a bit too quick to crowd you, which isn't something I recall being as frustrating in the original (although the pitch black darkness of the new one means they often get the jump on you). I was also disappointed that the "circuit breaker" mechanic wasn't used for better effect more often, there were probably only a couple of times where you had to make a choice between say, lights or life support. I was looking forward to more of those sections but they never came.
I'm hoping I found all the security override caches, I scoured the map intently looking for them all but it's not the best and not being able to set your own waypoint was a bit annoying.