The EVO line is the top shelf WSBK spec stuff. I is not the GP4 RR. The EVO uses 30/34mm pistons and has to be used with the EVO Master which is 17/18. The GP4 RR is a 34/36mm piston and can use the standard 18/19 lever. Regardless both these calipers are 108mm only so unless your going to swap forks or you have 108s already they will not work. Additionally the EVOs are race pieces only and have to be services accordingly and can only be sold to individuals under some with some restrictions (complete BS but that's what they say) and you need special rotor spacers to run these. So in a nutshell, no you don't want these. They would be complete overkill for just about everything and you would have to service them which requires constant removal, checking etc. Not saying you cannot run these on the street but they are a bit of work. The GP4 RX looks similar, is a 2 piece 4x32mm and works with RCS and comes in 100mm. That's a better choice for the street. The stock M50 is a great caliper regardless. For the street and track, it is way more brake than I could tax and unless you have to have some shiny things hanging off your fork legs, I would keep them. I use what i use because its part of the intended application and I'm probably a bit impractical due to the ability to be so.