I had my 7d fixed by CPS once (which they charged me £160 for). When it came back it needed a +8AFMA adjustment to be back in sync with all my lenses.
Problem I had is a few lenses already needed a +18 (and a +20) so canons actions rendered a few of my lenses unusable at wider apertures (namely 50 1.4 and 85 1.
I sent it back to canon for a calibrate. The said that it was originally calibrated versus their standard lens so they wouldn't redo it.
I had to get a third party (authorised) repair centre to recalibrate my camera (at my own cost). AFter which it came back fine.
Lesson learnt: I will never use the CPS repair facility again as they ruined the use of my 7d for a number of months.