Likewise, haven't bought a release title in ages, but after seeing the reviews and hearing people talk about it I really wanted it. I've also got Forza 4 and Arkham City on pre-order, which isn't like me at all!
Anyway.
I've just finished the first mission. So far it feels just like the first Deus Ex, which is great. I did most of the level very aggressively, just shooting everyone, but I'm usually like that - I lose my nerve doing stealth. I'll probably re-do it stealthily once I have a better feel for the levels, the AI, the game mechanics. I'm playing on medium difficulty and not struggling much for ammo, though I do have to swap guns a lot depending on what I have. The sense of exploration and investigation is good, with all the computers to hack and other things to read.
In terms of bad points... The enemy AI is pretty predictable so far, and when I've died it's because I've been a dumbass, rather than that they've outsmarted me. The voice acting is also pretty weak - I have no idea where that Pritchard guy is supposed to be from.
First impressions are very strong. I remember playing Bioshock and being disappointed that it didn't feel all that much like System Shock 2. This feels much closer to the original Deus Ex.