Hi Tom,
Building your own is a lot of work, but I always think they fly better

All the BLS servos I have had were really tight on the gears, makes for a very good setup. I have noticed on really calm days that I can see the difference with one beep on the lowest setting for trim with the 14z (when flying really long passes), thats a pretty fine level!
I have not tried the small ones on the elevator yet, might wait till next year since I have lots of 9650's I should find homes for!
Chad