best bmw dealer south east to use?

[cps]

hi,
help and advise please form your expert CSL owners view.. i live near reading and i want to have a bit of warranty work done on my csl as it's slurring into gear especially noticeable when dropping down from 6th to 5th when push on.. i don't think it's clutch as it doesn't have judder etc, just slow when changing gear even in 5th setting in sport.

so i'm not far from coppers at reading,

but i don't use my csl all the time, so i don't mind if i travel and I have a BMW warranty.

could anyone recommend best place to try booking it in? best reputation and good with warranty work etc please?

thanks for reading