Like SteveSRT8, I find that the StopTech Street Performance pads are exceptionally good performers, and I have run them on a number of cars on the track as well (HPDE, not for W2W) with excellent results. They have very good cold bite, they bed easily and quickly, they are not a weak link in terms of fade, and they're very inexpensive!
Pair them with high quality slotted (NEVER DRILLED!) rotors and it's without a doubt the best year round, high performance, high reliability setup I've used.
On the other hand, I have gone through a few BBK's on my 328, E46 M3, and my 03 M5 has a kit from the PO (he sold it from the shop when they were being installed, so while the 8/6-Piston 380mm/365mm APR BBK would not have been my choice, they do look wicked with the thankfully silver calipers behind the 19x9.5f and 19x11r Kinesis wheels).
StopTech, Brembo GT, Brembo Trophy, UUC/Wilwood, and UUC/APR have been on and off, but after getting Performance Friction 4whl kits for both the 328Ci (it has M3 axles/hubs) and the M3, both 6/4 380/365 kits w their 2pc floating vented slotted rotors, I have yet to use better brakes.
Changing pads is actually something I don't dread anymore, and I am currently experimenting with a variety of their pads to find the best for each Street, autocross/short road course, long road course, and endurance racin.
I wwill report back my findings!