We did last year, there is a good CG inside the south unit. The one we stayed at was a fair way off tho and I saw some around Medora. We also ran up to the North Unit and it was moderately interesting. I'd have to rate both as third class National Parks. Worth a look but no spectacular features. The south unit can have Bison but we saw none on that last trip.
There is a clear route to Glacier, get on US 2 and stay on it to Browning, which is a few miles outside the park. Switch to US 89 for the last couple miles.