It might work just fine, yours is a great mobo and will be 16x 4x vs my old 8x 8x. A lot more testing would be required to establish the difference between 16x4x, 8x8x and 16x16x. It could be that the Blitz just didn't like having two GPUs not in SLI/XFire. Sadly the interest in SoftTH from those who have the resourced to do these tests looks to be about zero.
What's your intended monitor setup?
I reckon the resolution on the side screens can be reduced even further with no impact on actual gameplay. Mind you I use the TrackIR; I find that I make use of peripheral vision in the side screens but only look at stuff in the main widescreen.
Water stuff is coming next week and I intend to OC the GTS a fair bit then... will be cool to see how far it will go. I bought the 320 GTS because I don't want to put the really big money on a GPU when the 9 series is around the corner...