Just to echo the Flyingfox’s comments, they are simply the best brakes I’ve ever used. They are the only brakes I’ve had that didn’t give me heat problems on long extended DH runs in Chamonix (where a DH run will last easily 15 minute) and I am pretty heavy also, so I’m working my brakes materially harder than a lot of people.
I’ve never tried to bleed them myself as the instructions say you need to have the lever pointing vertically upwards (at least on my versions as I think the newer ones may have solved that issue?) and you need a clamping system to do it that I don’t have (something like a seat post held in a work stand or vice etc.
I’ve used mine with Avid rotors in the past but they do work better with Formula’s own rotors. I think Formula rotors are slightly thinner than the Avid ones I had and The Ones have very little travel at the piston so with a thicker rotor there was much less clearance so unless your rotor is dead straight, they can rub incessantly.
I currently run the front with a non Formula 203mm postmount bracket and they work fine also.
One thing to be aware of. The metal on the post mount of the bracket is quite soft so make sure you use washers between it and the mounting bolts. I didn’t and I’ve work grooves in the metal which make it hard to set the brakes up without rubbing. I can get the caliper aligned but then when I torque the bolt up it pulls the caliper out of alignment.