What type of gun?
Angel: Never used a JT. Own, but never use my OTP G-3 anymore. The original o-rings on the inserts wear out after a few uses. The inserts didn't seat correctly, therefore lots of broken paint in the barrel. The inserts screw into the barrel clockwise, and screw into the frame counterclockwise. Result, over screw one way and it comes loose. Too many holes. If you're a slider or keep your barrel tight on a bunker (i.e. a paint oozing hyperball bunker), crap will get in the holes and game over. Swab, swab, swab. I've given up on the insert market, but I've read excellent reviews on the Equation set up.
I mainly use my boomie (smaller balls) and Cobra step bore (larger ones or when the Boomie doesn't shoot the paint well).