One note on this, not because I think it'll inform your decision but because I think it's importannt to understanding how to get the most out of the gain channel in a Mark - the EQ knobs on a Mark are pre-gain, the sliders are post. That means that the knobs generally impact how the amp breaks up, whereas the sliders are better for pure equalization. One thing you'll see a lot of guys, or at least did in the 80s in the heyday of using these for thrash, do is boost the midrange and treble using the knobs, but then go back and scoop the mids and maybe roll back a little bit of treble (or not, if they want a brighter, crunchier tone) using the EQ sliders. Increasing the mids and treble tends to further saturate the preamp of a Mark, which is one of the reasons you first started seeing guys do that midrange V. The reverse works well enough, too - I'm still finding the sweet spot in my V, but lately I've had a slight scoop in the mids, which has the effect of making the amp sound a little more open, I think, coupled with a slight mid cut and upper mid boost (annd slightly smoothed out highs) in the EQ section. In general, though, I'm trying to get my lead tone as close to where I want it without EQ, and then just use the EQ to get it that last 5%. Also, I almost never use the EQ on Ch1, which to be fair on a full sized V is really more of a clean/lightly gritty channel than it is on the 25 (where they move Crunch to Ch1). I don't remember if this is a feature on the JP2C, but on the V they give you a "preset" EQ curve of the classic Mesa V as well as a blend knob to control just how strong you want that V to be, and if you were looking at using one EQ curve for leads on Mark I on channel 2 and another for rhythm on Ch 3, then the preset blended in to taste is pretty stupidly heavy right out of the box (I rarely blend it in more than say 50-60%).