I am thinking of biting the bullet on this. I am tired of monkeying around with my ragtag assortment of pedals. Right now I have a stock Strat and a TRRI. Do I need to invest in an OBEL? Am I going to need anything else other than this contraption? Also, how long is it going to take to figure this thing out? Something that gets me 80-85% of Jerry's tone is just fine by me.
The Axe box, from what I've heard does a great job of replacing the amp (at least the pre-amp) and a bunch of pedals. You might still want an envelope filter of your choice - I don't have one but most of the rack versions of the Mutron III don't quite cut it. Vic or one of the others that use the Axe could tell you for sure. Are you looking to run direct? Into a poweramp? If so, then this thing is a good choice. Do you play a lot of other styles of music? Then this box is a good choice, lots of cool amp models so you can get your shred on too if you desire.
As to the OBEL - I would say this: it's a great thing for playing live. It gives you the ability to not have to do the stomp-box tap dance right when you need to be focused on playing or singing. If you gig a lot I think it is a cool thing for any live player not just Dead band players. As far as changing your tone dramatically, I am skeptical - other than if you mess with you volume a lot. Having a master volume on your guitar after the OBEL allows you to change volume at your guitar and not have your effects wimp out on you. If that sounds like issues you have then I would say the OBEL makes sense. I'm getting a guitar built now and I am probably going to put one in that guitar.
You can get a really good Jerry tone from a Strat and a TRRI - it won't be exact but good. Heck, if you play like Jerry you can get a good Jerry tone from a Flying V and a Marshall
I would put the OBEL money into a Super II in the middle and a unity gain buffer first; that will get you a lot closer to the Garcia tone off your guitar.
Caveat: I'm a bit biased on this subject.
I have been playing with the AxeFX and nothing else for a year now. I run direct to the board and into a pair of QSC K-12 or K-10 monitors onstage (one at my feet, like a vocal wedge, and the other behind me for front stage fill). I don't use any pedals or other devices, except for a Ground Control Pro to control the effects on the AxeFX.
It's a definite learning curve. My Garcia patch won't necessarily do you any good unless your guitar shares the same pickups and electronics (my Suhr Strat doesn't sound good at all through my Jerry patch, but both my Fender Strat with the DiMarzios and buffer, and my Tiger guitar, with DiMarzios and Waldo's buffer, sound great).
However, the learning curve is well worth it, because the box does so much more than just Jerry. It's limitless. To me, that and the fact that you hear better onstage than you do with a real Jerry rig outweigh the percentage you lose not using the genuine gear. And I had a fairly complete analog Jerry rig before.
The envelope filter I wrote on my AxeFX isn't exactly a MuTron (or a Q-Tron) but it's much more linear in its response across the fretboard and with a careful touch, you can get good results, especially in the context of the band:
(Excuse the audience recording the first minute. Hit the 480p button, sounds way better.)
As far as the onboard effects loop, I still use it, but with the AxeFX you can just as easily put a volume block after all the effects and control your volume with an expression pedal. But you do lose the advantage of feeding the "effects" with full pickup volume at all times if you're a volume control kind of guy. Me, I typically use a 6db boost for soloing and let my touch determine most of the rest of my volume.
Now, if you are still planning on using real speakers and a power amp, or just using the AxeFX for its effects alone, I would reconsider, because a lot of the strength of the AxeFX is the ability to use all the different amp and speaker cabinet-driver combinations. Some guys just plug it into a tube power amp and a 4X12 or something, but that's missing the point -- to me.