The JM4 DESPERATELY needs an amp model for acoustic guitars. None currently give you true acoustic guitar sound like AUX does, but AUX can't be looped separately from the vocal. Turning off the amp model doesn't work either, because the acoustic still doesn't sound right in this input. Because of this, I can't even use my mic with it, which breaks my heart because the MIC features are AWESOME. This one change would make the JM4 the perfect tool for the 1-man band, which should be the target customer. We could even eliminate our mixers. How awesome would that be? One perfect little box for EVERYTHING! All we'd need is an inexpensive A/B switch between acoustic & electric guitars.
Please go to Idea Scale, Line 6's place to submit ideas, and vote for my post (link below). Maybe they'll perfect this wonderful tool!