I ran the jp8hr in 21.5t tc stock on black crc carpet yesterday, along with a montech racer, type-s, and preopard. My fastest laps and best consistency came with the jp8hr. It felt much like a racer but smoother (which makes sense since the rear 3/4 of the jp8hr is 95% the same as the montech racer but with smoother features).
the only issue that i've been noticing with the jp8hr is that both of mine are twisted, as is the one that another local racer has. One of the front body mounts needs to be a lot higher in order to get the splitter to be parallel with the setup board.