I've worked with production companies for a number of years now and I've seen everything from multi-million doller equipment being run by some producer's son who wouldn't know his rearend from a hole in the ground, to a $1000 setup run by someone with an incredible ear and talent for sound. (And the brains to bring earplugs to every gig.)

Also, I've noticed that many times it's either the performer's way or the highway. I've worked with bands that trust the engineers judgement, and those that don't.

On the other hand, as a performer I've dealt with trusting a moron, and then having to tell him what I want and him looking at me like, "stupid musicians think they know everything."

From what I've noticed, unless the engineer has a lot of experieince in folk or traditional music they end up mixing it like rock...which sounds loud and awful.