I just had them do the TSB... long story. The clutch/flywheel are really known to take a dump in the '07 and pre-9/'08 GT500's. The TSB Ford released (more specifically) replaces the flywheel, clutch, input shaft, and synchros in the tranny, with new and better equipment.
After having the Shelby back last week, there was a very pronounced "shudder" right at 1500rpm in first, which is definitely far from normal. I took it back and I got kind of a weird feeling from them... since I dropped it off, the service guy told me that Rob (who did the work) has since ordered a new drive shaft, and a new piece that actually connects to the tranny itself...