Jon, your points are all valid and well made. If it sounded like I was attacking the M13, I didn't mean to. I like my M13 a lot, and I find it's great for some things, really great for a few things, and still OK for all the rest that it can do. I love the flexibility its many effects gives me, and I love that I can run them in any order, AND that it has its own external stereo FX loop, and that I can insert that into any position in the effects chain. And that doesn't even scratch the surface of what a motivated person could do with it, or touch on it's pretty-damn-useful 28 second looper. I bought mine a few years ago and liked it so much I picked up a M9 for my smaller grab-and-go setup. But then I'm a bit of a gear slut.
My main point, I suppose, is just that I've evolved my thinking on a couple of effects, especially the Mutron. I found that after upgrading my preamp, amp and speaker to what was recommended on this forum (SMS CTP, MC50, E120, respectively) and then upgrading my guitar to the UGB/OBEL and giving it a Tiger-esque pup selection, I can really
hear the warmth and tone inherent in various analog effects. Which is awesome and the whole point of these upgrades, lol; money well spent, but definitely money spent. The only "downside" is that now that I can hear these details I find I really miss them when they aren't present.
The music is still only going to sound as good as you can make it sound as a musician, and I'm still just a mediocre guitarist - effects don't supplant talent and skill, and I'm sure someone with actual talent could do much more with much less. But the JG setup is all about bringing out warm tone and clarity, and the original Mutron really shines in this environment. I think this sort of environment doesn't really favor the M13's Tron effect, and something like the Proton falls in between: better than the Tron, but still lacking the magical secret sauce of the Mutron.
My 2 cents.