Miller's isn't bad--but it's nothing special either. If you're on the west side of campus and you're too lazy to make the trek to Riley's (but have no intention of just settling on Miller Lite or whatever you can find at the BP)--that's what Miller's is great for.
It's a clean and friendly store, but their wine, wine cooler, and overall selection is kind of average. It's better than what you might find at a gas station, but it's not anything phenomenal.
The prices are fair for what they have. Overall, not a terrible place, but if you want something to write home about, you're better off somewhere else.