Thanks for the insight. As someone who is the opposite of an audiophile and can't really tell any of these differences besides volume and some weird sounds, I'll try to focus more when I listen back.
The overall volume differences have been most noticeable to a layman like me. Mike's vocals always seem the loudest. Emily's vocals vary sometimes, especially when she moves the mic away from her. Guitar volumes seem to change a lot depending on songs. I can almost never hear Mike's guitar in any of the recordings.