Surprising allround capabilities
Grippy in most conditions, braking traction, longevity
traction on rocks, must be run at the richt pressure, smaller than advertised
I've been using the Hillbilly in 27.5 x 2.6 as a front tire for the last 10 months. During that time it has seen all manner of conditions from dusty dry to muddy as it gets and I've ridden them on local enduro trails and in the bike park.
Though looking like a predominantly wet weather tire it has impressive grips in almost all conditions I encountered - provided you run them at low enough pressures. I found that when ran in the 20 to 22 psi range they worked like a charm. Conversely when ran at higher pressures they felt as if they didn't conform to the ground enough, thus becoming bouncy and slippery. When ran as they demand traction is impressive in all areas (cornering, straight-lining and braking) and in all grades of steepness. While not beinge the fastest rolling tire it never seemed to drag me down noticeably, so the got it got that going for it as well.
What I like a lot about the Hillbilly is it's longevity. While my rear tire which has been run for the same amount of time looks fairly used, the Hillbilly doesn't look much worse for wear, so definitley a decent investment in my book.
Though it shined most of the time I found that on rocky surfaces (read rock slabs, rock gardens) it felt soapy and unpredictable. Also the tires are fairly narrow for the advertised 2.6 inch width, which did bug me more than it should have probably.
All in all I'm definitely a fan and can recommend this tire for anybody who rides in varying conditions ond not too rocky, enduro-y trails.