This was our second trip to Lisbon, and we had a great time and were very happy with the Old Corner House. Carla was a very gracious and welcoming host, and provided us with a lot of suggestions for the kinds of things we were looking to do and explore while in Lisbon.
We chose the Old Corner House in part due to its location in Bairro Alto, which was an area we hadn't much explored during our first visit to Lisbon. It is described as a generally quiet neighborhood that comes alive at night, and this is accurate if not an understatement. There are dozens of bars and restaurants on each block, and while many are charming and quiet, visitors should expect a lot of noise late at night. Earplugs are highly recommended. Frankly this was a bit much for us after a couple days, so we tended to go to other neighborhoods for dinner or drinks. All that being said, the location is excellent, with very quick access to several neighborhoods of Lisbon, and the Metro and train stations are close by.
As for the house itself, the description on the post is accurate. It is cozy and comfortable for a short stay in Lisbon. As noted on the description and in various comments here, the bedroom is really only suitable for sleeping, but is otherwise comfortable. The kitchen and bathroom are also fairly small, and while this is typical for an older neighborhood in Lisbon, it might feel cramped if you are more accustomed to a bigger house. The amenities were all fine (internet, tv, soap and towels, etc.), and we were very happy to have a washing machine since we had been traveling for over a week already when we arrived.
Overall we had a great stay, and we'd happily recommend the Old Corner House to anyone looking for a great home base from which to explore Lisbon.