I've had both, and have video of both. In my opinion, the SC-Project is louder and the Race fit has a better tone. The SC-Project would ring my ears in high rev even with earplugs whereas I've done several track days with my Ravefit with earplugs and to me, it doesn't sound much louder than my Arrow Slip-on but is super loud to everyone else.
And to answer your question, neither remove the cat. SC-Project nor Race fit
Youtube: Xyst Patterns
#3 2015 Daytona 675R (Track)
#7 2008 Ducati Multistrada 1100S (Street)