I just thought I would post up the link to this site. While they don't test every possible tire, the one thing that quickly becomes evident is that you cannot look at a tire and tell if it is fast. It would seem that the compound and casing are much more important than tread pattern.
I've followed this site for some time now, and it's always interesting how Schwalbe always comes out on top. In real life I tend to agree with his findings, at least it's my perception.
Add one more who's found the site interesting and also wished more tires were tested.
I was really entertained to see and compare the new Race King Protection 2.2s that came on my Fargo with Small Block 8s I have on a bike and against the Schwalbes a friend so believes in. The 2.2 Race Kings feel really quick compared to the 2.1 Kendas I have on a bike. The test proved it. No wonder I'm surprisingly happy commuting on 2.2 MTB tires.
If his website is correct, he buys most of his tires himself. It'd be nice if brands would donate them for testing but I don't think they want the bad publicity if all their marketing is wrong.