I fitted mine a few weeks ago, absoloutely no problems with running/fuelling or performance. The benefit of the GP Pro is that you shouldn't need a PC. It has a loop on the intermediate pipe to simulate back bressure after the stock cat has been removed and also had a 18mm boss to take the lambda sensor so no O2 eliminator required. If you run the stock air filter then running should be ok. Guy, I'm a mechanic but these are a peice of cake to fit, remove lower fairing panel, flapper cable from servo motor, RH rear set, o2 sensor and cat/can can be removed, simple. If you get stuck just mail me at Gmail (stevenhrc@). Like most people on here, i run with the baffle in as way too loud without!!
How to install Two Brothers Racing exhaust for 08 CBR1000RR - YouTube Check this out Guy this helped me it's not a Leo Vince but you get the jist
