I've been riding the Racing Ray SpeedGrip HS489 up front with the Racing Ralph Speed Addix HS425 on the rear. Caveat - any new tire setup (to me anyway) feels great compared to worn tires that I just replaced no matter what kinds I've ridden. That said, my initial impressions compared to a wide variety of XC tires that I've ridden over the years (mostly Maxxis Ikon 3C, but also Specialized Fast Trak, Conti Race King, the older Racing Ralph, Schwalbe Thunder Burt) are (1) Cornering - Excellent, I really have to push these hard compared to other XC tires on my well-known trails to get them to break loose, under a variety of dry conditions (2) Climbing traction very good with the new Racing Ralph, probably a bit better than the old Racing Ralph (3) Rolling Resistance - hard to say but likely no worse than the Ikons (4) Durability - TBD. I've only ridden the combo about 10-12 hours but so far so good. (5) Installationtubeless - a bit tough to get the last part on the rim, but not impossible.