I don't know why so many people have feedback problems mic'ing instruments. We do it all the time. I refuse to put a pickup on this 1933 Gibson because it was once owned by Scotty Stoneman. This was last New Years eve, and this place probably seats 300.
I am now usually on a barstool and also play a resonator that doesn't have a pickup so just mic the guitar as well, since it's easier than constantly changing things, I just move the mic a little.
I LOVE the sound of an SM57 just a few inches from the guitar, but it does take a little practice to not BANG into it.