A thought probably so obvious it hasn't needed stated...

   I think performance and volume context can (or should) be a contributing factor to accompaniment, as well. As a somewhat fledgeling guitarist playing w/o a sound system, I've found that playing feathery arpeggios in a bar, coffee-shop, protest, or dance situation is pointless, no matter how great it sounds in a quiet room. My musical partner and I often create more complex arrangements, and then have to suddenly abandon them in favor of energetic flatpicking for performances.
    Obviously, if we had pickups, a great sound system and quiet environs, complex gtr/mando bits could shine. But the situations we find ourselves in, we more often need to get the beat and the sound as loud (or at least as carrying) as possible... Recorded, it would sound unsubtle and clunky, but in a noisy sitch, it can be appropriate accompaniment.
    I wonder if a similar phenomenon plays into M Mcleod's critique of Dennis Cahill's guitar work... If it's more suited to a noisy dance, and, given a seated audience and amplification, it ends up sounding mis-matched?