Yeah the noise gate is pretty poxy. Its pretty much like switching from a single coil to a humbucker, in that the noise is reduced, but it's still there when you crank it up. It's probably the most annoying thing about the amp so far, followed by the fact that the mid knob doesnt really have to go further than 5, at least with the EL 34's that im assuming my JSX came with (the shop was a bit clueless as to what the amp was other than what was in the catalogue).
After reading this thread i actually plugged into the low gain input (intentionally) for the first time today. Even then it impresses me for the softer side of my playing. It seems like one of the most, if not THE most versatile amp going around.
Daniel