Crysis 2 sucks balls when you play online.
If you enjoyed the first one this one is a good sequel to it, although the graphics have been lowered for the console versions but still a gorgeous game. It's fun and easy to get used to and there are many ways to do the missions, stealth, run and gun, different tactics, stuff like that.
Online is terrible, if you are not picked host, you will be 2 bar or severely lagging. Terrible connections that have but they are fixing it.
But in the mean time, borrow it or rent it before deciding your choice of purchasing it or not.
Also if you want, look at some walkthrough's or playthroughs of Crysis 2 and see if it's something you like.