Having lived near a roundabout for 6 years, I have become a huge fan of them. In general they are safer, more efficient, calm traffic, and more aesthetically pleasing. They are also very good at dealing with intersections where not everything is perfectly aligned at 90 degrees (Highway 14 and Marion Road is a great example). As a taxpayer, I love that operating costs are much lower than a signalized intersection. There is a large roundabout planned for US 63 and 75th street North.
One down side is that roundabouts can be intimidating for cyclists especially if they have multiple lanes or higher design speeds.