My pics, bunch of locals;
http://s95.photobucket.com/albums/l145/bigjohnskona/Dalbeattie/
Mabie is the fast & flowing one.
Dalbeattie has a lot of techy, pedaly bits
Niether have much in the way of climbs compared to GT/Inners
There is a jump/freeride park @ Mabie. Log rides at Dalbeattie.
If you are fit enough do them both, only 1/2hr apart. Cafe @ Mabie.
If you could make it on Thurs I am not working till 6pm, get the "locals" 