It is what it is. I think Marcus meant to sell you the stars, but they forgot that in the end, it's just a movie theater.
The whole ticket/assigned seating thing is annoying. Just let me go in and find a seat. The kiosk ticketing is also annoying. It's slow. It sometimes takes multiple hits to enter information. The whole Marcus Rewards card swiping thing doesn't work properly.
Then, the snack counter is as inconvenient as it can be. There's no sense of flow. You have to leave through the same line you stand in to get there. The drink counter is equally annoying. Too many people, not enough machines.
The theaters themselves are nice, although it sucks having to share those two-seaters with a stranger. Don't hog my armrest, dude.
It's not horrible. But it's not great, either. Going during off-times (like weekday mornings), will help alleviate most of the issues, but you will not catch me there after 3:00 pm any day of the week, and I will avoid it like the plague on weekends.