I don't monitor in the field, but mix and edit with both headphones (ATH-M50) and loudspeakers. I'm most comfortable with loudspeakers and use headphones for practicality (keep quiet for the family) or as a double-check -- so I voted loudspeakers.
Likewise, I do sometime record A-B, or mix in an A-B omni pair with near coincident cardioids, but choose the near-coincident pattern as that is my primary.
I don't have a fig8 mic, so blumlein and MS are out. I found long ago I don't prefer XY having tried it with a number of mics, though I haven't tried it in years. I also run small diaphragm exclusively. There probably is a lot to be said for XY with large diaphragm mics, but for SD doing concert taping -- the stereo spread of the PA is already pretty limited and room reverb is always a challenge, so getting the right stereo image when only using included angle (in XY) vs using mic spacing + angle (for near coincident) never seemed to work well for me. Also, the slight phase comb filtering that comes with near coincident seems to sweeten the brighter mics that I seem to prefer.
Sorry, not meant to be a near-coincident vs XY debate, I just thought my decisions on pattern had more to do with all that and not listening playback type. Still, I guess the more exaggerated stereo separation with headphones might have made me happier with XY I suppose.