I demo'd 2 bikes with Crossmarks...nick named them "Death tires"... other may like them me..I could not corner on them seriously I slid out on a couple turns that I had no business sliding out. I do like the Nobby Nic 29 2.25 Snakeskin, expensive but has been very good to me in SoCal looseness. Of course so many trails are so loose right now because of the drought those trails for me are just not as fast as they can be. Spesh dare I say.. Purgatory is a big heavy but capable tire... I liked the Eskar better but they don't make it any more... What rims do you have do you have real UST if some you might try some of the WTB tires.