Well, actually i recorded it with a Sm57 AND the AT4047. The Sm57 alone sounds like crap, too boxy, too much hi mids, and too much stuff going around 300hz (which probably tells me i have acoustic problems..). Also it is too hard to fit on the mix because it gets either too loud, too quiet or too trebly/thin. I usually also have to cut a lot of low mids or else it will sound too distant.
I just tried the AT4047 once, and not actually on a real mix (i recorded over a client's song) and it imediattely made the GOOD low mids come forward, so it's way easier to make the song work. The Sm57 brings the hi mids and punch it lacks.
I mic'ed my cab with the SM57 on the middle of the dustcap (about, maybe 3 feet away) and the 4047 just at the side, pointing at the outer side of the dustcap ,with the capsules aligned. I tried every damn position, and unlike when using two dynamics, whose phase invertion brings a lot of fizz and a little bit of mud, with those two mics, besides a little bit of fizz, a good amount of low mids also come. So, maybe it cancels some of the mud i get on my mids with a dynamics-only setup.
Anyway, i'll be recording guitars on wednesday, and i'll take some pics and record some samples so you guys can listend a little bit.