I stayed here last year, and while by no means the best of Starwoods, it was not the worst. There is no club floor/room and while I am a Platinum, no breakfast was offered (in fact, now that I think of it, no amenity was given)??
It is near a subway stop and a 10 min walk from the main train station as well as 10-15mn walk from the Duomo and the main sights of Milan. Would I stay there again??, probably for the night stay credit, but only if I got a cheap rate. As for other things to do in the area, how about a very short train ride to Lake Como? You can stroll around the town, and take one of a number of ferries to the beautiful lakeside villages. Or take a bit of a longer train trip to Torino (it looked pretty interesting with all the Olympic promos). But there is also lots to do within the city of Milan as well. Aside from shopping and the Duomo, there is the 'Last Supper' (but make sure you have a reservation to see it, as you can't just walk in) and lots of other areas to explore.