Purnima is a wonderful host. The house is located just off a main thoroughfare, but the place itself is very quiet. While Inman Square is a little far from downtown Boston, it is in itself a great place, with a couple nice bars, a Whole Foods, etc. The Hubway bike share is convenient, and takes about twenty minutes to get to central downtown.
Purnima is very friendly, was welcoming even when I got in much later than originally planned, and instantly offered me a cup of tea. The room was very comfortable, with plenty of blankets to stay warm, and a space heater if that wasn't enough (I didn't need the extra heat, though). The kitchen and bathroom are neat and modern, with a personal touch of style.
The only potential downside is that if there are other guests in the adjacent room (Purnima's other listing), they may be noisy and the shared bathroom might be a little inconvenient. Don't let that dissuade you, though, because this was an excellent experience all around.