This is a little animation test done with Vray 2.0 RT - GPU.
As you can see in the end of the video, the graphics boards renders just above 12x faster than the CPU.
If you take the price into consideration, then the GPU is 6 times faster. - Not too shabby :-)
There are still room for lots of improvement with the RT software, in particular the GPU code! But it's still very usable for a lot of applications - especially simple studio scenes like this.
BTW. On my website you can find some free 3d models of rugs as the one in the animation. - http://www.bpositive.dk