Re: GTS 250 from 8800 GTS Upgrade - Worth It ?
What GTS do you have? If you have the 320/640 series like I did I say why not. I went from an 8800 GTS 320MB to a Radeon 4770 (trades blows with the GTS 250) and the increase was unbelievable. Of course I game at a much higher res so the difference would probably be more noticeable to me than to you.
Edit: Also that at res even with moderate AA/AF I don't think you would benefit much from the 1GB version.