Final decision is nearing....
7900GT(the new EVGA KO version which is stable and has no problems):more stable, much better drivers, almost no chance of power supply problems as it uses almost the same power as my 6800GS earlier, system 'purity'(meaning pure Nvidia components and no interoperability issues), and faster boot-up(the Ati X1800XT took longer, my on-board 6100 boots in a snap, the X1800XT used to display a weird corrupt pattern for sometime, even when it ran fine), about $60 cheaper, more than adequate performance at 1152x864, the max my current CRT can handle at decent 75Hz refresh.
X1900XT: Faster, upto 40% in some cases, HDR+AA, 512MB, but crappy drivers(no flames please but ATi drivers just don't hold a candle to Nvidia's),potential PSU problems, weird HSF(spins up and down during games and is quite irritating sometimes),MIRs to deal with
May be a poll would be better...