in answer to your question, all the new ‘tech’ brakes share the same lever. this is a love it or hate it item depending on how you set your brakes up; if you like to run them quite inboard and brake one fingered with your index finger then they are great, if you run them closer to the grips then they can be a bit tricky to set up next to shifters. the hope website shows you how to do it though. the x2 caliper is like the old mono mini- great brake for xc, good feel, maybe a little underpowered. the m4 is a 4 pot caliper with a bit more grunt at the end of the stroke, still lots of feel though. i loves ’em. the v2 caliper is the big boys brake, dh type thing. last time i looked merlin had the best price but that was a few months ago now.