Would the 512mb nVidia Geforce GTS 250 set me back from the 1gig?

Ok so I went to Fry's and bought a 512 MB nVidia Geforce GTS 250, and when I got back home, and just strolling through the internet, I saw that there was a 1gig version. If I were to play say like Crysis, (lowest setting) would there be any drawbacks for not buying the 1gig version? Thanks