I'm slowly going thru the game. I did about 1/3 of it (i think) on normal mode - planning to do all the achievements thencome back the second time and just worry about finish it hardcore... then changed my mind (that game isn't hard) and started over again.
I'm going to rage if something bug'd out and i don't get non-leathal and not setting off alarms. :)
i'm having a great time! the only thing that stresses me is missing the e-books. But Every zone, once cleared, lets you back track - so before i'm about to leave a zone i check to make sure i got all the books :)
I missed one in picus and had to ride that god damn long tram back up and then kill all the guys i blocked out of the room :P