This place is amazing. It comes as advertised.
I was there with my 4 kids for 5 days, and it was never too cramped. It's well situated on Beacon Hill and easily accessible. There's a Whole Foods nearby, making getting groceries easy. There are also a bunch of restaurants right below the apartment. We walked everywhere, the longest walk being to the Aquarium, about a 25 minute walk.
Only downside was that the temperature in the apartment was not that consistent but that was surely because of the freezing temps outside. I'm sure it's fine when weather is better (there are AC units, for example).
There is a private washer and dryer available, which was very helpful with 4 kids!
Anyway, I'd come back, if only for Jay's wonderful and helpful communication!