Last time was coming down the Campsite Descent On Long Mynd. Its proper fast the whole way down, but the last bit especially so. Anyway, loads of walkers, so much hard braking. Just got to the gate as my front lever went squishy. 180mm TechM4 with a 10 stone rider on. No problems since mind.
I had no end of problems with my old Formula The Ones (200/180).
...and a pair of black/gold Hope mono minis, that never did anything but fade. Horrendous brakes. New seals, pads, fluid. Nothing changed it. Simply they didn't work.
Oh, and had it in the Passat coming down Alpe d'Huez in a bit of a hurry...