This is an exceptional flat. It's enormous, well-appointed, and quiet. As noted by other visitors, it is about a 15 minute walk from the historic city center. However, the neighborhood immediately around the flat is wonderful, too. Just a couple blocks north there is an excellent supermarket (Co-op) and several fun restaurants (some traditional family ones, and other trendier, stylish ones), and you'll probably be the only tourist in any of them.
The free, on-site parking is very convenient, but the entrance is narrow, so if you rent a car and want to park it there, get a "compact" car. An "economy" car may fit (ours did, but with only 2 cm to spare on each side), but anything larger probably will not. Just in case your car won't fit, Alessandro provides directions to a garage a few blocks away, where parking is about 20 Euros/day.