I'm always looking for tire reviews so I figured I'd review a couple tires I'm familiar with...
I jut got some Maxxis Raze and I'm basically comparing them to Ritchey Speedmax which I was using previously. They're a lot faster than the speedmax, roll much easier and excellerate quicker, but they don't have the same bite on corners. This isn't an issue with the rear, it sticks just fine, the front though always wants to wash-out on me, which is just how my bike is for some reason.
So I've got a raze in the rear and a speedmax in the front and the bike feels a bit quicker.
I'm mainly riding on dirt, lots of loose stuff, and the rear hooks up nicely. I like it on grass too, better than the speedmax, but again the speedmax has much more cornering bite.