I can't say enough good about these tires. I've ridden Maxis, Continental, Michelin, Kenda, Intense (yes, they made some tires awhile ago), WTB, etc. over the years but these tires, made by Vittoria, seem to work the best for me.
I ride XC in the Wasatch (PC) and some in Idaho (SV) and these tires are great for the conditions seen in these two locations. The tread pattern is just burly enough, they hook up when needed, roll fast and are durable. I will say that the tires are pressure sensitive so if you choose to ride them, fiddle around with the pressure until you find the sweet spot. If you do that, you won't be dissapointed. I run speed-front, traction-rear on my 29r SS at about 25 psi (tubeless) and I've found this combination to be a winner.