That depends on many aspects, there still are people out there, that don't have 20+ Monitors and still go with a CRT, at 800x600 (32 Bit) most games (if not all) look more then decent and move alike with a X1600 (I own one so I talk about facts), now it's true that a GF7600 GT was better at that time, but some developers like Palit released an Hybrid like X1600 Pro with GDDR3 at 170$ wile a GF7600GT was 250$ (same as XT) - at that time 7600GS from Gainward wasn't available and the versions with GDDR2 weren't very promising - I made a comparison between this two - and even with 4 pipes the GDDR3 looked more promising, among 7600GS based on GDDR2 (at same price).

x1600XT and x1650XT both outperform the 7600GT
This is wrong, GF 7600GT was sometimes 20% - 30% better in FPS then the alternatives from ATi, but all depends on peoples needs and obsessions, cause I Honestly can't understand the people that like to play games at 1600x1200 with all at max, as an ex professional gamer (still am gamer, but not professional) I say 800x600 and 1024x768 at 32 bit is more then enough for a decent play if you own a CRT, on LCD-s 1280x1024 would be a native resolution and that's another point of view but 1600x1200 is insane, an obsession for max resolutions.