I have been to Dexter's quite a few times now, usually for their specialty tappings or to watch a football game.
Atmosphere - I would classify Dexter's as hole-in-the-wall hipster-esque classic Wisconsin bar. It will appeal to people who just want to go to a local pub and crack open a Hamm's. It will also appeal to people who want an unassuming space to quaff some delicious craft beer. It isn't fancy, but it is roomy. My one complaint is that it is always chilly. I usually keep my coat on or I freeze.
Food - The food at Dexter's is pretty good. It is slightly amped up pub food. It is most certainly better than your standard pub fare. They have some yummy options for spicy, heart-clogging sandwiches that my husband loves. I like the Fajita salad and pulled pork sandwich.
Beer - Fantastic. This is real the reason to go to Dexters. They have rotating taps of featured beer. They are attentive to trends in craft brewing and will often have something that is new and difficult to find. Their bartenders are usually knowledgeable about the beer, and they know how to pour a hefeweizen correctly. It is not the best deal you will find in town, but they will also have pours other places don't get.
Service - Also pretty good. I have no complaints about the staff here. They are attentive without being annoying. They also know what they are talking about which is refreshing.
As a plus, in the warmer months, they have an outdoor space you can play volleyball. Or you can join their volleyball league.