I've never eaten *in* here before, so I can't speak to the service or decor much at all. It's pretty dark is all I can so.
Marrakesh catered for a Thomas Piketty book club event we had, and we ordered tons of stuff: meditterean (sp) salad, hummus, vegetables, and chicken tagine. All of us thought the food was off the charts, and I didn't think it was too oily and greasy at all (like I sometimes do with Moroccan restaurants). If you are looking for ethnic cuisine that's less commonplace in Madison, I'd definitely check them out.
They are a little hard to find because of poor signage, but with a couple U-turns, you should get to it without trouble.