We stayed at Marla and Coe's flat for almost two weeks and had a great time.
What to expect:
Expect a gorgeous apartment that is both very spacious and very functional (not just "nice to look at but don't touch anything" but nice to live in and to feel at home instantly) with a nice kitchen. There is a great collection of good books in the flat and also a nice selection of books on Boston and the wider area just outside the flat and the hosts are great - nice, interesting and fun.
Of all our AirBnBs this one stands out as probably the nicest apartment and the nicest hosts. Can't praise either highly enough!
Don't expect the flat to be very central:
The following might not apply if you have a car or if you use Lyft or Uber - we only used public transport. Boston is a great city to explore on foot and using public transportation (a 7 day card for all public transport for 21 USD is a steal!).
To get to a specific place downtown (e.g. the ferry to Provincetown, the start of a duck tour or similar) you're looking at about 45 minutes to 1h to commute (walk from the Apartment to Dudley Station, Silver Line Bus to Downtown Crossing, walk from there). Dropping off your shopping at the flat and getting back to downtown will take 1.5 to 2 hours.
Don't expect a "hip" neighborhood:
The neighborhood is residential with a mix of recently renovated houses mixed in with boarded up ruins and everything in between. We felt save on the streets (and everybody we encountered was friendly) but there is not much to do in the immediate neighborhood - just one restaurant (Merengue, Dominican Cuisine), and a couple of mini-shops that sell the barest essentials. Other than that, there is nothing. If you want to go for coffee or for something to eat, you have to go to Dudley Station or head into town.
So in a nutshell: We really really enjoyed our stay. We really loved the apartment. We enjoyed our great hosts.
In hindsight if we might have chosen a differently located AirBnB (in a more lively area or in an area closer to downtown) - but we would have missed out on what made this trip special for us. Highly recommended.