if ah looks fine for you, happy lad. running a gf3 or gf4 wonīt enhance gfx quality (well, not unless you enable those gfx gimmicks), but the frame rate will jump into regions where you donīt have to worry about smoke and furballs making your pc 'stutter'. this at even 1600x1200x32bits res (presumed your monitor supports this res at all).
the fsaa (full screen anti-aliasing) fuzz is all about some technique to smooth those jigsaw edges that appear on the screen when diagonal lines are being imaged by your gfx card (think of the canopy frames or the wing edges in ah for instance, they will look much more 'realistic' when their rendered with fsaa enabled, especially when those parts are moving relative to a background). want me to me into detail? donīt think so *ggg* anyways, all those fancy gimmicks like fsaa (see above) or anisotropic filtering (some method to sharpen all that textures used in 3d. will make the ground textures or the planesī surfaces look more detailed for instance) are taking considerably more memory bandwidth (max possible amount of data per time unit that can be moved between the cardīs ram and the cardīs processor.) than the standard gfx modes. your gf2mx isnīt able to provide that bandwidth, so trying to enable these features will most likely totally hose your frame rate, to a degree where the game wonīt be playable at all. the gf3 and gf4 cards can easily handle these heaps of data and will provide playable frame rates at even the highest possible res, and all gfx gimmicks enabled. a gf4 card however, will do slightly better than a gf3 card.
youīll have to know if itīs worth the extra cash. if youīre happy with the way ah looks right now and just want extra fps, go with the ti200. youīre not going to notice any difference in fps when switching from, letīs say, a ti200 (or radeon8500 if you like so) to a ti4x00 (again, the human eye canīt tell between 100 and 120 or 130 frames a second.) ti4x00 only pays for those who want to run fsaa and similar at max res.