Here, I took the time to research all the options when looking for my tune:
DBC Tuning____________APR
Black Jack Speed Shop___GIAC
SoulSpeed_____________Revo
BD Tuning_____________Unitronic
I have personally gotten work done at Black Jack Speed Shop on my GTO, full coilovers, swaybars, every single bushing in polyurethane, front and rear subframe alignments, and they did an incredible job. Even asked me to bring the car back a week later so they could double check everything is tight and aligned. The shop is owned by Tim Duncan, they do alot of R8 tunes, I can vouch for them.
SoulSpeed also has an amazing rep, they are known for work on high end racecars, Porches especially. They and Black Jack Speed Shop have the only 2 corner balancers I know of locally.
I had my VAGCOM done at DBC tuning, another of my friends had his K04 CC done there. A good shop from what I can tell. The downside is they are usually very busy, I waited 2 weeks and still couldn't get my tune done.
I can't comment on DB Tuning as I don't know much about them.