I have had nothing but excellent results using several sets of REPCO pads on a 535i and now my 300CE. ( I think they were bought out by another company and go by another name now.)
The primary benefit is far, far less dusting than OEM pads. Stopping power, I think, is comparable to OEM. The only downside is that you might occasionally get some squeaking on the rears, but it sounds like you didn't need those anyway. But the fronts come with the teflon anti-squeal pad so they're quiet; the rears didn't.
Some argue they're harder on the rotors, that may be, but I have yet to detect that. Rotor replacement is relatively inexpensivvec and should be done at some regular intervals when warranted anyway to maintain effective braking.