We spent 4 nights there in Apr 2017. We stayed in the hilton chain, Back Bay Area (not downtown) it was walking distance to downtown. We picked it as it was close to Fenway park, the fine arts museum, close to home straight of the marathon, in a brown stone area and handy to everything. It was an easy day walk through the gardens, up to Paul Revere house, old north church and the ship yards then a ferry back to the aquarium area and a cab back to the hotel. Another day was was a walk to to tea party museum, children’s museum, china town for lunch. Sounds like a lot of walking but with a 9yr old in tow it was not that difficult. If you use trains, these are also easy to use, we caught a couple.
Finally, unless the laws have changed just be aware if booking accomodation with lounges MA laws do not allow “happy hours” so if you stay in hotel that has a licensed bar, it is unlikely (based on our experience) that the hotel lounge will provide complementary alcohol.