Resolution Worth Giving up Detail

Solution
The best upgrade I have ever done was going from a 17" 1280 x 1024 to a 22" with 1680 x 1050 on a 8800GT card. The GTS250 is a more capable card so I would say yes.
I went from a 19" @ 1280x1024 to a 21.5" @ 1920x1080, its certainly a significant difference and i didnt even have to lower detail levels almost at all, i cant throw on AA but i dont really feel the need to. Im using a 512MB 4850 which is about even with the GTS 250.