I always bring a backup guitar in case I break a string mid-set. Then, depending on the material we're playing, I'll often bring my Series I 12 string or my Orion Baritone. If I'm using my synth, my alembicized Fernandes (with 13 pin out) is always along for the ride. I recently picked up a Line 6 Variax. I may start bringing this one to do multiple duty, covering the roles of back-up, 12 string and any other sounds I may want (dobro, open tunings, sitar, etc).
Bill, tgo