Federica's apartment is perfect in so many ways. The location is very convenient, just a 2-minute walk from the same Metro line that goes to the Central station and to the Duomo, and a 10 minute walk to the fun neighbourhood of Isola where you can find great bars and restaurants. The apartment itself is gorgeous, furnished with great taste and with tonnes of character (thanks to the gorgeous sloping wooden-beamed ceiling!). The kitchen was well stocked and the bathroom sparkling clean. We also slept very well at night, so it's safe to say that the bed was nice and comfortable. I'd love to stay here when I'm in Milan again.
PS - Federica was very helpful, super accommodating and gave me lots of tips on what to do in the neighbourhood.