GPU upgrade

Hello guys.

I am considering an upgrade for my current PC before I build a new rig (considering building it around Q4 2013). I currently have AMD Radeon 4850 and I have an offer to buy GeForce 8800 Ultra for a very low price(35€). Will it boost my performance somehow? I mostly play Planetside 2, Assassins Creed games, Crysis and other similary demanding games. Do you think it is worth it?

Thank you for your time! :)

Ouroboros

the 4850 and 8800Ultra are about the same performance

you wont see much of a increase if any, the 4850 might actually be better

Thank you for your response :) I looked at numerous benchmarks and it really seems that the 4850 is better (and is less power hungry).

Have a nice day ;)