I don't know anything really about CryEngine 3....but the first Crysis and second Crysis are FUCKING HORRID ENGINES.
The AI in BOTH games are a joke. In Cyrsis 2 there were many instances where the AI was running in place in a corner. Then The first Crysis is one of the worst optimized games in existense.
B/c of the first 2 Crysis games....I will not by Crysis 3 until it's like....shit...$2.