I have had mine on 3 different bikes for the past 4 months (yeah I change bikes a lot).
First set of Shimano brakes I have owned (coming off avid). I cut the lines, pushed a new barb in and haven't bled them yet, still on the factory bleed. I am super happy with them, even on 5 min+ runs in NZ they wouldn't fade a bit. Still on original pads even after riding every weekend, mostly in the mud.
Cannot recommend them highly enough. I am going to a Saint front caliper, purely because I will use the Ice-Tec caliper with the M775 lever I have.
So yeah, basically they are the best set of brakes I have ever owned and I guarantee you will be happy with them. Dont go with avid unless you enjoy weekly bleeding. Running mine with RT75 rotors 203mm front and rear. I also weigh 70kgs.
GET THEM.