After manufacturer's rebate counts as a minus for sure though.
And the X1950 PRO clearly has the lead at stock speeds, so that's worth a little heat and space methinks... if you're overclocking the GS, it's going to use create more heat and use more power, too.
Not everyone likes rebates.. but my point is there is less of a difference than maybe what the OP thought. Valid points about overclock. I still don't like the design and size of the 1900 series, that's one reason I would pick the GS. Also, I've have bad luck with Asus in the past, maybe I'm biased.
I also want to point out the eVGA 7900GS I listed has a 50 Mhz faster core and 60 Mhz faster memory.. so it is better than the Foxconn 7900GS in that comparison article.
No amount of overclocking on the 7900GS would get the performance to the level of the x1950pro where it really counts, look at the difference between the minimum FPS recorded in Oblivion, the ATI is 2x faster (who cares about the max fps value, I care about worst case senario)