Yes if the issue of heat noise and power are factors get the quieter cooler and less power hungry card being the 7900 GTX.
In benchmarks its faster in some games its faster of couse it cant do AA and HDR at the same time but IMO who cares.
I think some porkies are being told with HDR + AA in terms of frames in games and this seems to be the only arguement people have at the moment with regards to the x1900.
And the funny thing is whats 50 quid saving at the top level of pc hardware?
Nothing IMO.
I shouldn't have to fit an after market cooler on my 350 quid gfx card to make it quiet.Making the financial gap between the x1900 and 7900 GTX closer still.
Ill install my 7900GTX and have silent,and I mean silent top end cool gfx power thankyou very much.
But everyone is different.