I've used Live to sequence synths from MIDI loops, but not pre-recorded audio. The biggest problem is if I/the band gets out of synch with the pre-recorded stuff (brain farts, CRAFT moments, inadequate foldback). It also makes everything a pre-set length and structure, which isn't always desirable, and controlling Live on the fly while playing something else isn't simple.
One of my local musicians frequently gigs using the largest Boss loop station and gets very good results. I forget the model number, but the current equivalent is the RC-300.
She plays electric rather than acoustic, but uses the looper to play back pre-recorded backings as well as live some looping. Basically she constructs the loops so that she can switch between e.g. intro, verse, chorus and solo backings at will. The advantage over simply playing back a pre-recorded backing is that if she decides she wants to solo for longer (or shorter) or drop a break in rather than going into a verse she can do so at will (useful for the times you forget the first line of the next verse :-) ).
The guitar runs into effects then a Sansamp before going into the looper, and the looper runs direct to the PA.
She's at the mercy of whoever's doing the sound at the venue of course, but we all are to a very large extent anyway - and if a sound engineer can't e.q. and balance a vocal mic, maybe an acoustic instrument, and a stereo line input without problems then stand back and pretty much leave the mixer alone, frankly they're in the wrong job.