When I saw the listing and the price I wondered if it was too good to be true, but this place is as nice as advertised and it's larger than you'd expect. There are numerous thoughtful touches and as a host Lynel is responsive while still granting privacy. An extra-rave review for being pet-friendly. Overall a great experience.
If someone had trouble with stairs I could see it being less than ideal. Especially light sleepers may not enjoy the proximity to the train, but this can be offset with calming music (there is a nice Bose radio in the bedroom), or earplugs.
If you're looking to take advantage of what Jamaica Plain has to offer the location cannot be beat, but the amenities are nice enough that you'll be strongly tempted to just stay in. I was.