We stayed in Michele's apartment for the 5 Days of Italy orienteering races. The apartment is located in the southeastern outskirts of Madonna di Campiglio, on a quiet residential street, yet just minutes of walk away from a small supermarket and the little lake, and maybe 10 minutes from the main shopping street; it also borders the forest, thus a perfect location. The apartment is small, but quite functional and lovingly decorated. Being tall, my main problem was the low ceiling height in the kitchen (which we solved by exempting myself from loading the dishwasher :-)). Michele was extremely quick and helpful to respond when we had questions about how things worked or needed local advice. His housekeeper Natalia was also very helpful.
While predominantly being a (expensive, from the looks of some of the shops) downhill skiing resort in winter, nature is stunning all year round, and there are numerous hiking trails as well as some mountain bike paths, all well sign-posted. Some of the ski lifts are open in summer as well in order to take hikers into the mountains, a feature we made use of quite a bit. (The "5 Lakes" hike is strenuous, but extremely stunning and highly recommended if you like mountain hiking.) While Madonna has all commodities and a very good selection of restaurants, we'd also recommend an outing to nearby Canisolo and Pinzolo, which are more authentic mountain villages.
Our favourite hangout in Madonna was "Café Campiglio" with nice ice cream creations and aperitifs. Lots of dinner options, "Le Roi" had quick and courteous and very professional service. Be sure to try "carne salada", cured meat, a local speciality.