I actually have a JSX head and a 2 Channel "H" to compare. It has been awhile since I used the JSX (and that was with a Boogie OS 4x12), but I have some opinions.
First, the clean is not as clean on the PRS as it is on the Peavey. The PRS has a breakup and drive to it when you crank it up (as was mentioned, Bassman esqu).
Second, the Lead channel of the PRS is, gain wise, somewhere between the two gain channels of the Peavey. It can do everything that the JSX Crunch channel can (gain wise) but not as much as the Ultra channel can. I find this to be just fine as I never pushed the Ultra channel of the JSX to its limits.
Third, as was mentioned, the mid point is different. It's in a different spot than what MB or the Big M offer. However, I really like it. I thought that I would miss having the the third channel for solos or higher gain stuff that the JSX offered, But I really don't due to pedals and rack gear. The PRS seems more open than the JSX (which is odd considering that I find the JSX an incredible amp!) Maybe it's the EQ curve and mid point selection, maybe it's the circuit design, maybe it's voodoo. I don't know. My Sewell found a way to ring 10% more of of a classic amp design.
In the end, it really depends upon how you play and use the JSX and what gain levels you want. I have been through the incredible line of Peavey amps leading to the JSX (Ultra, Ultra Plus, XXX, and the JSX) and they really fit my style. But the PRS are that with a whole lot of "MORE". I can't put it into words (although I tried), but I think that a 2 Channel "C", 2 Channel "H", or Custom 50 might be right up your alley. The Archon, to my ears, seems to be in the market with the Dual and Triple.
But this is just my opinion being an owner of the JSX and a PRS amp that you might be interested in.
