Last Saturday was my second time to this Monk's location. I've been to the Wilderness and downtown Dells locations many other times.
The first time to the Sun Prairie location was average. It was the new place in town so everyone was trying it, and the wait was always ridiculous. It's died down a little since then, but it really depends on when you go. We were looking for an early dinner before the Badger game on this second visit, so really had no troubles getting seating.
Our service was much improved on this visit. Our waitress was great, very attentive and checked in with us often. Food also came out quickly. We both ordered burgers with fries on the side. I had the "It's All Gouda Burger." My burger was good, and I ate about half of it before having to box it for the road. We also both ordered sides of ranch for the fries. FYI they do charge for these!
All and all I would say this spot is improving. They did build it on the small side, and I'm hearing that there are already plans to build on to make it larger. I think that should have been an obvious issue when building, considering the location and that there's not much else around there for restaurants.