Which one is more powerful: 1)- 2000lb bomb (Nanosuit) 2)- 2KT thermonuclear warhead (Iron Man) That is kinda what you are asking.
Ironman suit of course, it didn't need to be recharged every couple of seconds, could fly and totally invulnerable to normal bullets :arnie: Worse, Nanosuit 2 isn't much better, and IMO it looks fat :nerd:
MASSIVE SPOILER (not like you didnt figured it out after 20min of playing Crysis 2 anyway, i did lol) Nanosuit 2 is alien tech and iron man is human tech. Heargrave looks dumb if you consider what Stark could do with purely human tech
Seriously? Comparing the two is like comparing a Koenigsegg CCXR to a bone stock Tata Nano and asking which one is faster... Iron Man suit all the way; bulletproof, flying, no need to recharge every few seconds.
Another vote for the Ironman suit. Although, the nanosuit can cloak..but the Ironman suit would switch to thermal sensors, radar or some other detection method I suppose.