that would be mics in front of the amps. anything else means more stuff to route, issues with ground loops, compromising the tone, etc. etc.We almost never mic the guitar amps and I'd like to see that change. Since I'm stuck doing virtually all the PA work, I'm looking for the quickest method possible to get signal(s) to the board with a minimum of headaches.
you can hang 57s over amps with OK results, but sennheiser e609s are made to do that (as is the nicer e906 which i use on my guitar amp).