I wouldn't buy a new SLI board when "maybe" getting second VGA 6 months later.
Propably you will see the performance difference only at high resolutions with AA/AF enabled.
This is how i feel...about the whole thing....I used to like nvidia...the Ti series kicked ass...but then the 9700 pro came out and the 5800 Ultra at the same time...and omg...the 9700 pro still manages to play all the new games with ease...and the 5800 basically turned alot of people away from Nvidia. Then we had the x800 pro and the 6800 Ultra...at this point Nvidia finally got rid of that stupid FX thing..lol...and made a card that performs very very well...as did ATI. Alot of people at this point were arguing more over drivers and Nvidia made the better drivers...but ATI (in my opinios was still the better card) was achieving the higher scores when the 5.0 drivers came out. now we have the 7800 GTX and the R520 slated to come out...from what I can see is that the 7800 GTX will be bad ass...and it is avalible!!! the r520 is having problems trying to get all the pipelines working..so I dont know...Nvidia might win this round...I will stick with my 9800 pro though because i run everything out there still and i cant justify spending 600 on a graphics card..let alone 2 cards for SLI!!! So if i were you id get a 6600GT or an x700xl or x800 pro..one of those cards will last a long time and are all made very well.....oh...and ATI's new drivers 5.7 and 5.8 are supposed to boost ATI's line by 30% I mean wow..their driver team are really moving in leaves and bounds.
both cards perform well ....
but I will prefer nV ... I had a lot of small (and some not worth to mention) problems .... but they existed
while I haven't found anyone of them for nV
for 6800 also the power consumption is compare to its performance very very good if not the best
everything just works as expected ...
and give a shi* on 30% performance gain .... NO one will optimise a driver to have 30%+ performance that is simply impossible if there is no mayor bug.