A lot of good, but a lot of bad too
On the Pro side of things: Location is great, 2 blocks from Boston Common, convenient to Beacon Hill and the Back Bay. The customer service is very good, the furnishings in the room are modern, great bath products, and every room has a small balcony. They have a small gym and a nice pool.
On the cons: I kid you not, the hallways smell like vomit. Either they use the worst smelling carpet cleaner ever, or the Emerald lounge crowd that it caters too has too much fun and can't make it to the bathroom. The hotel caters toward the Emerald lounge, they offer you VIP access for staying at the hotel which means at 2 AM you hear the drunkards running up and down the halls and being very loud. Those 2 things alone really contribute to the downside of things.
If you are not young and looking to party all night, I would not recommend this hotel. Unfortunately the crowd it seems to cater to overrides the positive aspects I listed.