Despite the now massive array of microphones on the market
many pro engineers still use 57s for mic'ing amped up guitars
although it is also not uncommon from what i have read
for top pro studios to try all sorts and perhaps even mic up amps
with loads of different mic's including expensive large diaphram capacitor
mic's such as Neumann U87s etc
and then use the combination of the many mic's to create their own sound