I used ADP for some hour building Summer 2001. It's cheap and the admin staff are good. From what I saw, the instructors are pretty poor, and the singles fleet is aesthetically tatty, although maintained where it counts.
Top tip: Stay in the local Shilo Inn (free pick up/drop off) rather than ADP's residence. You pay a bit more, but the other customers around who were staying at the residence seemed pretty damn wierd. + you get a swimming pool at the Shilo.
Anything specific just ask I'll try and help.
Dave.