No the AI is by far not sufficent.. its even worse then in the first game... wana see how bad:

Just made made a few minutes into a random level in replay:
http://www.youtube.com/watch?v=o15nllSS7ns

You can basically finish all levels with cell personal that way, and even most of the basic aliens grunts fall for the same cheap playstyle. Whoever thought it was a good idea to allow more then on shot in cloak mode and staying cloaked obviously never played the first game... In crysis 1 cloak already was pretty much op... now its god mode.