I'm sure you're aware of the upcoming Fishman wireless Triple Play guitar synth, if you plan to use external synths modules/computers, i'd bet the tracking will be better then any Roland synth, I used to have the Axon AX 100 and it worked great, the Triple Play is designed by the same guy, so i expect even better performance, and the fact that it's wireless will be a big plus. I'm waiting for them to start shipping to pick one up, for now i picked up a Roland GR-20 which works pretty good as far as tracking the internal sounds, which are just ok, it's not so great using it's Midi out with external synths, but can work, I tried a few GR-55s at the stores and didn't think the tracking was any better then the GR-20, and didn't care for any of the amp modeling. Unless you really need the guitar modeling part of the GR 55, I'd just wait for the Fishman Triple Play, don't think the Midi out of the GR-55 is any better then the older Roland GTR synths, but I cold be wrong I didn't test the Midi out to a module, just internal sounds.