Here's my expierence:
Seen toce bros on both an R6 and R1. Stupidly loud for street use, to where it doesn't even sound good..and could easily get you tickets in low gear. Both bikes did have race headers though, so that would be different sounding with a cat. Also heard it is really hard to clean them up and make them look new again, but I can't back that up not owning this exhaust. Way overpriced for what it is IMO
They look pretty good though, something different for sure. If you want it, go for it. Also, search this forum. I know there are a few toce threads here.