I enjoyed my stay. The place is in an excellent location in the Back Bay, where all of the activity is. I was across the street from a CVS, which I loved. The room was nice and presentable upon my arrival, with the bed made and everything. The host communicated proactively with me and responded promptly to any issues addressed.
I do want to note that while the ad says "apartment," it's really more of a hotel room. The building is comprised of about 12 units and is like a hotel without a front desk. If you look at the unit photos carefully, they show in detail its size, which is not that big. (The fireplace in one photo is in the building entry area and is not part of any unit.) The bathroom in particular was small, which is uncomfortable for larger people like myself, but it's manageable. It might be the best one can expect for the heart of Boston. Note that you do need to climb stairs. Unless there's something I didn't see, it is not wheelchair accessible. The shower water heating time was inconsistent - I think it depends on how recently it was used somewhere in the building. It helps to have the shower pressure on fully (for which there is a separate switch). Finally, when I first walked into the room, it has a strange smell, though it could have just been from the humidity. I got used to it within a few minutes.
Other than that, I enjoyed my time there and would stay there again.