i took my M 4-5 times and so far I'm happy with it.
I work nearby so always I do same day service. Drop my M, take their shuttle and shuttle pick up again.
They're pretty good with same day service (compare to BMW Encinitas) and their warranty work was pretty good as well. I complained about peeling airbag emblem and steering wheel trim then they replaced with brand new airbag and trim without any questions.
I have a modified car (see my sig) and never gave me hard time for anything either.
So if it's same day, routine work (nothing super complicated), I have no problem taking it again.
PAST: 14 F10 M5 | 11 E70 X5M | 08 E90 M3 | 08 E92 335i | 03.5 E46 M3 | 99 E36 M3