The rooms have plenty of room for 1-2 travelers. I have stayed in smaller rooms that were meant for 3-4. All the rooms are nicely furnished. There is ample A/C for the summer.
The location is an easy 5 minute walk from Sint Pieters station. The surrounding neighborhood is very nice. Citadel Park is only 2 minutes of walking.
The owners are fluent in English, French, and Dutch, and I'm not sure how many other languages. Conversation was easy. They also generously provided maps of the city.
The price was very reasonable.
Last but not least, the breakfast was great! Every day, we were served hard boiled eggs (fresh from Pieke's chickens), a wide assortment of breads and jams, traditional pastries, chocolate, and good coffee and tea. The fact that I can still remember what I ate for breakfast over 6 weeks ago should tell you something of its quality.