Just beat it in my third and final session (4h + 6h + 8h) as well and I have to say it was one of my best SP experience, easily better than HL2. I played on Delta and the last few levels were just breathtaking, pure adrenaline rush and even the ending fit nicely and I'm really looking forward to Crysis 2.
I played the whole game at 1080p with Gaco's 1.1 config and performance was good vs. image quality, always enjoyable and never unplayable! The last level (after the indoor cutszene) was a little slower but a restart helped a lot to ease up the pagefile. I haven't noticed any bugs in the whole game and none on the carrier level.
I'm not often happy with my game purchases but this one was worth every damn cent! Great job Crytek!