I've been using a set of Hope's new Mono Mini brakes since last Christmas and I have not one bad word to say about them. Even in stock form with the alloy levers in place of the lighter retro fittable carbon ones I now have fitted, they're feathery light.
Yet, unlike some other super light disc brakes which can feel a bit flimsy in use, the Hopes are rock solid. Still, some racers complain about the weight of these things, so Hope decided to create their lightest Mono Mini to date by peppering the standard brakes with high grade titanium bolts in the lever perch, pivot bolt, adaptor bracket bolts, rotor mount bolts and frame fixings, they've added their aftermarket carbon lever and you still get their super light floating rotor.
You can still specify whether you want the braided hoses or the standard black ones, but the result is a disc brake set which at 295g is light enough to go on even the most fussy XC racers bike. The £170 price is per brake, and that's £30 more than the standard non-Ti Hope Mono Minis that weigh 375g.