We can echo the previous reviewer of the Cos Cob Inn not being what we expected--not bad, just different. The Inn is in a large house, but has a distinct hotel feel to it. I don't think it should be classified as a Bed & Breakfast by any means, since breakfast is just a continental selection and not a meal served from the host. You park at the inn, walk across the street to an office and get your keys from a receptionist. Like the other reviewer, we didn't see another soul the entire time.
We stayed in the Venice room on the third floor, a quaint room with a decent sized bathroom and a very tall and comfortable queen bed. The room is stocked like a hotel--TV and mini-fridge in the hutch, mints and chocolate treats on the table, iron and ironing board in the corner. The rooms are done by numbers and not by name when you get in, which adds to the hotel feel. Aside from some leftover wrappers from previous patrons, the room was very clean and had everything we needed. The only complaint would be the window overlooking the front of the house and the "water." You actually have a pretty good view of I-95 and the thin glass/poorly sealed window leaked a lot of noise. Climate control was a bit lacking as well.
We chose Cos Cob Inn to help split up a long trip from Maine, and the lack of a full breakfast meant we didn't feel bad getting up early and leaving before food was put out in the common room. Our checkout was as simple as leaving the keys in the room, so we didn't have any trouble on our way out.
All-in-all it was like a nice, small, quiet hotel with perfect amenities and nice rooms. It's no B&B though, so if that's what you're looking for, look elsewhere.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.