I had the pleasure to stay at the Carriage Bar Guest House during a one night stay in September 2013 for the Clarence DeMar Marathon. Upon arrival, I was warmly welcomed by the two very kind owners who were accommodating throughout my stay. My room was clean, spacious, and comfortable with a queen size bed. The bathroom was also clean and comfortable (although yes, the shower was a bit small). The location is nice with a short walk to the magnificent downtown area (the town of Keene, by the way, was just fantastic). I do agree with a previous comment about the walls being a bit thin, although it was not problematic for me per se. I enjoyed the lounge area and the nook looked very nice (although I had to leave early and did not eat the breakfast).
Overall I thoroughly enjoyed my stay at the Carriage Barn Guest House and will stay again next time I visit Keene.