*Apparently* I've seen some people hit 900MHz with a decent voltmod, and if I ever get near that number (I think it's with 1.35 VGPU) then I will definitely need an aftermarket cooler.
I think the S1 is very transferable too, so whenever I sell my GTS in the future, I can always replace it with stock cooler.
I placed my order, $46 including taxes and shipping, with the Turbo Module fan attachment.
And... I also placed an order on a cpu/heatsink lapping kit
It's just a set of pieces of sandpaper, cost me $4 so whatever, and I get the following grits: