Let the hive mind of Engadget get that for you.
"I just switched to Sprint from Verizon about three months ago for the Pre. Then I went for the Hero about a week ago. Now, I miss my hardware keyboard and am thinking about switching to the Moment. I am still able to switch back to Verizon if I want and get the Droid when it arrives. Should I just trade up to the Moment when it comes out, see if I like it, and if not switch to the Droid? Or something else entirely? Help!"
It is the fastest because it's selling and has benchmarks to back it up. Xscale is also a market-proven SoC.
Snapdragon is still vapor paper-stats with no backing anywhere, and comes from a line of SoCs with a history of under-performance and empty PR. All this Snapdragon fluff has only hurt it.