I agree that the rock isnt the greatest quality and can be sandy and greesy, but if it is dry in the afternoon it is great and very convinient. I still think if you want to beat heat of the valley Corona Del Mar is good.
Black Mt is the greatest bouldering area (beats horse flats)I can think of but it is quite a haul, but well worth it. Just take a left somewhere on a dirt road on the way to Taquitz and drive straight up it for awhile and there you are in miles and miles of perfect boulders. I know these are crappy directions but it must be on a map somewhere or something. At seven thousand feet this place is lots cooler than Stoney and about five thousand times the size and it is granite not sandstone.