Worth the upgrade?

[chimaera]

So is this worth £150 to do?

From....

XFX GeForce 6600 GT 128MB DDR3
http://www.overclockers.co.uk/acatalog/6600AGP_Series.html


To....

PowerColor ATI Radeon X800 GTO 256MB

http://www.overclockers.co.uk/acatalog/X800_Series.html

My 6600 doesn't do too bad, but i could do with a bit more power for games i want like X3 and COD2.

I have a shuttle so i think the X800GTO is the best i can get, since i can't fit any dual slot or extended length cards.

All opinions welcome