Upgrading dual 8800 GTS to dual GTX 275

Depends on your resolution. If you are playing at 1920x1200 or x1080 then yes. Anything lower then I would wait for FERMI and price drops.

Yeah I use 1920x1200.

wouldn't it be better just to get a 295 or better

Then I would recommend it. Are you a firm Nvidia customer or are you willing to go red?

Firm Nvidia lol. Not going to the red side!

Why?

im going red soon

One of my very first computers had a built in ATI chip. One of my brother's very first computers had a built in Nvidia Chip. It ran a lot smoother than mine. Keep in mind these computers were like less than a year apart so there really wasn't a big difference.

I'm sure they have. But I've had nothing but good experiences with Nvidia, so why change?

To save some money?

LOL dude if you're talking about computers from back in the day, A LOT has changed. Namely the company that owns ATi now, AMD. AMD has turned ATi around and has made nvidia push back further and further their release date of their new GPU's. At the moment, ATi IS king of the hill.

As for will you notice a difference going from 8800's to 275's? Oh, hell yes. 1 275 will beat the performance you were getting with 2 8800's rather easily. But then again 1 4870 will beat both of your 8800's rather easily as well. And it'll cost a hell of a lot less than a 275.

XFX also is now making ATI cards so you have that awesome lifetime warranty that they've always offered!

I went SLI 8800 GTS to a GTX 275 and saw a nice performance increase.

If you want to SLI in the future you need to consider what mobo have you got, if it is only capable of SLI then nvidia is the way to go, if it can xfire as well than take a look at the ATI cards as well.

yeah I think sti's good enough
besides go for 5xxx for added DX11

At 1920x1200, you will likely see a nice performance increase if you play demanding games.