Mautari did some really impressive work with RadeonPro! Makes you wonder why AMD have been unable to do this for their own cards (they seriously need to hire this guy!).
There are some drawbacks though compared to the nVidia solution. Most notably the fact that you need to benchmark each game individually and then calibrate RadeonPro for that game according to your benchmark results. Tom's Hardware said in the review that it's a complicated and time-consuming procedure. Do it wrong (even if you're off by just 10fps) and you get some massive lag spikes (right up to 100 millisecond frames, which equates to a drop to 10fps).
With nVidia on the other hand, you don't need to do a thing - the hardware is already designed to deliver...