Which card should i pick 260 or 275 GTX

Monzer_

Honorable
Nov 19, 2013
12
0
10,510
So i currently have Asus 450 GTS not fancy ye i usually play WoW and BF3 on Mid :) so anyway there are these 2 cards Gigabyte 260 GTX and 275 GTX used but really good offer so i was searching and I read that those 2 cards only support directx 10 but mine has directx11 so is it worth changing to one of those cards ? or should i keep mine. would it be so much difference if i picked one of them over my 450GTS ?