depends on what you're playing
I had the single and dual rectifiers and hated them
I also had a peavey rockmaster preamp, which was the circuit base for the JSX and liked it much better for some metal stuff
it was much more in your face sounding, with very tight bass response, cutting upper mids and had a dense wall of midrange (tighter, middier and more dense sounding than a peavey 5150)
the drive is not much versatile, though, despite of the active controls being much more responsive
no 3D sounding distorted chords here, only full power chord brick to the head 8)
it's more articulate than the rectifier on single notes, though
but I think rectifiers are less dominating over the rest of your rig
the peavey ultra series (xxx, jsx, rockmaster, 3120...) have that "emg" feel that makes everything sound similar even when you change pickups, guitars, speakers... which can be great if you want to get the same tone most of the time (in a tour or rehearsing at different studios with different cabinets)
if you're in the US it might be worth the experience, but mesas are much more expensive anywhere else
but if you're playing thrash metal or some kind of metalcore, the jsx is one of the best amps you can get
