Played first two hours or so. Definitely good stuff. The stealth isn't annoying like I fear in most "stealth action" games, and the RPG moments far outweigh the stealth imo. I'm playing it as non-lethal/stealth, until bitches decide to aggro me and then they're good as dead.
I love the praxis/augment system. A good skill tree is all I really need to keep me hooked in an rpg -- and side quests, tons of side quests.
It hitches some on me when I come to a new area, probably just my old(ish) CPU is my only bottleneck. It's not enough to make me rage though and not play.