I would highly recommend staying on Boylston Street with Sonder. The location was perfect for walking to downtown or exploring Capitol Hill - honestly, I was surprised at how accessible everything I had planned to do was from this hotel's location. The rooms were clean, check-in/out incredibly easy, and while we never needed to contact any staff, I felt that I would easily have been able to based on the instructions in the app.
The building is a bit noisy although that didn't bother me as I'm a heavy sleeper. Sonder is aware that it is noisy and includes ear plugs and a white noise machine in each room to help combat it as well as "quiet hours". All around it was the perfect stay for me.