Stayed here for 5 nights with our 25 YO daughter. We really loved the unit - it was very well laid out and comfortable. The 2 BR's are on opposite sides of the unit, so they are well separated. The beds were especially comfy - we loved all the pillows and fluffy bed clothes. The kitchen is functional and open to the dining and living area. The bathrooms are roomy - especially in the master BR. The living room couch was also (surprisingly!) super comfy. We had just come from a 7 night cruise, so the W/D was really awesome to have in the unit. Overall, there is lots of space - although much of it feels kind of wasted.
The location was amazing!!! We were able to easily walk pretty much anywhere downtown (Freedom Trail, Faneuil Hall, Beacon Street, Boston Common, North End, NE Aquarium, Seaport area). We saved a lot in Lyft charges!
The not good: The unit is on the 7th floor and the elevator was out for our first 3 days. We weren't advised of this until a few hours before our arrival even though some folks staying in the same building said it had been out for a few days before we arrived. We were promised someone would help us with our luggage but after a half hour waiting on the stone lobby steps (and then hearing it would be another half hour before someone would be there), we ended up bringing our luggage and groceries up 6 flights of stairs. Not a problem if you're young and don't mind stairs, but we seniors really struggled (especially that first day).
The unit was also pretty warm (75-78), although it did go down a bit (73-75) after a serviceperson came by. There was a single fan to help with the heat.
That said, I'd definitely recommend the unit with the caveat to beware of the potential for the elevator to be out.