The guys @ the Lecht have done well with what they have, managing to squeeze 2 runs out of the space available to them. Not sure if there's enough to keep you entertained for a whole day. We went up not long after the first run opened, and had a good day, although most felt it was too expensive.
You could always join us for a night ride on Sat, for charridee mate. Details from CycleHighlands in Ballater.