Couple of follow-up thoughts. First is that the M13's models, while good, are not all great and you are probably, first and foremost, reacting to the fact that it's Tron model is simply not as good sounding as the real deal. Second is that, although I shared my settings with you, if your attack or the strength of your pickups or other factors differ from mine (as they certainly would), my settings might not be the best ones for you - you'd need to experiment for yourself. Last is that for many of the LIne 6 models, changing the controls slightly can impact the tones greatly. The M13 is not a "sounds great at any settings" device at all - tweaking is the name of the game (though it's very easy to do as the design is such so each effect model's controls are WYSIWYG).
And BTW, I tweaked my own Tron settings slightly, recently, from how they were set the last time I posted them here in my own effort to improve the tones. Time permitting, I'll re-post the updated settings, along with my full Grateful Dead scene (a scene is a combination of 12 effects on a single board, for those who don't have an M13; the M13 allows for 12 scenes (more, actually, but 12 is enough for most of us). And I haven't even mentioned the global settings the M13 offers like it's highly effective and transparent noise gate, as one example (I sold my Decimator gate shortly after copping my M13 - just didn't need it any more).
Which brings my last point. A device like the M13 is not for everyone. I think it works best for someone like me who's in a Dead cover band and plays a lot of Dead BUT also jams and plays with many other musicians doing a lot of other music. If I was completed Deadicated to the Dead, I'd probably prefer a trad pedalboard, too, loaded with all of the best pedals specifically to copy Jerry's tones. If this is you, by all means, focus on that one guitarist's tones. Myself, I'm playing Dead one day, U2, Weezer, and Goo Goo Dolls the next. I'm not a millionaire. I can't afford 12 pedalboards for 12 different types of music. With the M13, though, in just one relatively small footprint unit, I can carry around with me well over a hundred different effects set up in 12 boards that I can access one to the next with the tap of a toe.
This is the true attraction of the Line 6 M13 to me.
Somewhere, on a forum just like this one but dedicated to The Edge rather than Jerry, a conversation very similar to this one is ongoing where one person posts how he loves his M13 for U2 and another person responds, "Are you nuts? You can't get anywhere near exactly like The Edge with that unit!" And the person responding is probably sounding just like me here, ending with, "If you're extremely picky about sounding exactly like _______ or recording and need to nail his tones, I agree. Otherwise, here's what I like about my unit."
"For me, I think the only danger is being too much in love with guitar playing. The music is the most important thing, and the guitar is only the instrument." Jerry Garcia