I stayed at Melissa's place for three months whilst on a fellowship at Harvard. It was absolutely perfect for my needs: bright, spacious, clean, comfortable, well-furnished and about a 10-minute walk from campus (not so close that you get 'campus fatigue!').
The rooms are all a great size with big windows and it's really well-equipped for both studying and relaxing. If you're keen on cooking this is ideal as the kitchen is really fully-stocked with loads of spices and baking ingredients. Really, this is just a lovely, liveable space.
It's also really well-connected, with lots of buses and blue bikes nearby plus T stops at Central and Harvard, both about a 10-minute walk away. There's 2 Whole Foods both about 10 mins walk away and some cheaper supermarkets about 20 mins walk (or a cheap Uber/Lyft) away. Loads of great options for cafes, restaurants and shops as it's so near Harvard, Central and Inman Squares plus all the delights of Somerville.
Melissa is a great host who is always super responsive to queries. I had barely any problems over the course of my stay but if something broke she was really, really quick to get it fixed and always really friendly and gracious. I would really recommend this place!