arv_foh
Brian K
I would definitely have a cabinet for stage volume/feel at the very least. You can't always trust you'll have a good monitor mix, but you'll always know how your rig sounds in various situations. Really take the time to find your best speaker/sweet spot, mark it off with tape, and insist (kindly) that the engineer mic the speaker there.
FWIW, not every engineer (me included) uses sm57s for guitars.. So you could end off worse than you started. I never go by taped "sweet spots" because I know more than likely it's not going to work for me.. A good engineer knows their mics and knows how to place them.. And the ones that don't.. Well you're probably fucked from the get go so your tape isn't gonna help much. Just my perspective from working with lots of bands/shitty tones etc