I don't really have a strategy for ? vs. monster rooms unless I can think of a specific purpose:
if I take the first 3 enemies have 1 HP reward from the starting event, I'll go ? hunting for an elite path. (I used to think this event was a waste but being able to get through half of act 1 for free is pretty good, and it lets you be a little bit riskier. +6/7 hp isn't really all that great.)
one important thing is that you get enough decent cards to balance out your strikes/defends before you hit the act 1 elites, especially gremlin nob. a card like Headbutt isn't great or anything but it's better than a strike when dealing with lagavulin's debuffs.
if I get cards that offer bonuses in battle like: feed, alchemize, self repair, genetic algorithm, wish, lesson learned, hand of greed, etc then I'll prioritize encounters.
if I have toxic egg, I might hit more ? in act 2 to see if I can get the apparition event, since they'll be upgraded. I guess the same is true for the bites but bites are really situational and I've usually removed 2 or 3 strikes by then anyway.
various relics like tiny chest or whatever can offer some more value for ? events.
my HP dictates a lot, so if I have like 8 hp and a campfire is coming, maybe hit the ? events.
but outside of those very situational uses, I'm not really picky. I just do whatever I feel like at that moment. if I thought about it, I might say that act 2 ? events are overall better than 1/3 because of stuff like the apparitions or that event where you can get jax or transform 2 cards. but I dunno.