Amplifier modelling is the best thing to happen to recording guitarists since the invention of the Floyd locking nut. In my opinion.
I have been unable to get a decent bass patch out of this thing, though. I know it's theoretically possible (albeit it is a guitar effect unit) and there are instructions on the Line 6 web site. I should try following them sometime.
This is one of the few pieces of equipment that made me scrap my existing recordings and rework them, this time with the lead and rhythm guitar using the POD. I didn't know what I'd been missing.