one of the guys on my team has one. it has a seal issue, and only shoots 250fps.
its kinda stupid what GG did making it "adjustable FPS" so that you can cheat at the chrono by reducing the setting and then going away from everyone and turning a screw to make it hurt people.
I liked my JLS, but as some of you may have heard some retard took the fuse out of it thinking "that will remove all resistance" when in fact it kept the gun from protecting itself against catching fire. its gotta have something in the wire to prevent taht (mosfet, fuse, whatever).