the m4. imo,hope really do make the best brakes out there, totally modular,reliable,great looks and performance. you will hear horror stories about noise but fitted correctly and the rotors cleaned now and then with brake cleaner you wont have a problem.
i have a m4 on the back at the mo but i cant get it set up to work properly and has only the power of a vee brake. i have a coyote dual and am of heavy build
need a bit more information mate what cant you set up properly?did you buy the brake second hand?does the lever feel spongy? are the pads contamanated? is the caliper centered over the rotor?
the brake was second hand, but its had new seels, rotor and been bled since then. the caliper looks to be centred over the rotor but it catches on the pads in some places. so i thought bent rotor... but got new one and still the same problem. pads and rotor are fine. now im outa ideas appart from getting a new set up!