No more than using an arranger...

Using an SMF is no different to using a style. How much are YOU playing? How much is the machine?

That's the difference. Most of my SMF's are drums, bass, and maybe a bit of guitar. Played for years in live bands, and I was expected to cover EVERYTHING else. I don't feel comfortable doing anything less, even as a solo.

Let's face it. Holding down a chord, and hearing a full accompaniment issue forth is as much 'lip-synching' as pressing 'PLAY' on the sequencer and hearing the same full accompaniment issue forth!