I had CCB's on a series of Ferrari's (360 CS, 430 Scuderia, 458) and over the years CCB's have become progressively better. The generation 1 CCB's on my 360 CS were tricky when cold and I nearly rolled into my gates several times when starting out. All of my CCB's have had some squeal, I can't speak for the M4's as I have the standard brakes.
I always joke with friends that the reason I like CCB's is that they keep the wheels a lot cleaner, the problem is its a really expensive way to keep em clean :-)
Personally if you are not planning on tracking the car and don't mind cleaning your wheels more often then I'd stick with the standard brakes. So far I've found my brakes to be massively powerful with no fade/squealing etc. just my 10cents
