We did a summer golf trip up there several years ago. It was fine, but I highly doubt we go to Boyne again.
The courses themselves are good (and some great), but the vibe is a little strange there (in the area in general). You feel like you're in a time warp, as everything is very dated (rust-belt, after all). The locals told us they can't get/keep employees because it's too expensive to live there.
Bay Harbor, for instance, is a really high dollar course ($400ish green fee)… They've got a nice balcony with a restaurant overlooking Lake Michigan and Quarry #9 green. Awesome setting… The issue is, they have almost no one working it and they actually recommend that you go out to the food truck in the parking lot for service. I'm no golf snob, by any means… but when you're playing $400, you'd expect a little more.
At Crooked Tree, we had the 7:40 tee time… We asked about drinks and coffee…
Guy in the shop: "No problem! When the bev cart girl gets here, you can get it from her."
Us: Great! When does she get here?
Him: Usually around 9…
They literally had ZERO food/bev until around 10 AM when we saw her on the course. And post-round they actually ran out of ALL bread products… so no hotdogs, burgers, etc.
Highlands: Be sure to play The Hills course at Highlands. It's BY FAR the best at that facility. Very, very cool course.
At Bay Harbor… you really need to play Links/Quarry. The 3rd 9, The Preserve, is fine, but it's nothing special (and zero lake views). Links, specifically, is an awesome 9 holes and the Quarry has a great finish (along Lake Michigan).
Crooked Tree is fine, couple of holes with nice views.
Overall: I don't regret going, but I doubt I'll ever do it again. Compared to other golf trips, this one just doesn't measure up. It's not the easiest to get to and they just don't tick all of the boxes that you'd like.
To me, for a nice/budget golf trip, I'd much prefer RTJ. RTJ is more serious about their golf, IMO, and RTJ is way cheaper.