Sylvain's apartment couldn't be faulted. It was in a quiet area just steps away from rue Saint Jean and a 10 minute walk from the old town, so it was close to all the major sights. It was very clean and recently renovated to a high standard. Sylvain himself was very friendly when we met him on check in and on the morning of checkout, and made sure we knew he was just upstairs if we needed anything.
We would absolutely stay there again if in Quebec City, and would definitely recommend it to others (as long as there are no people with mobility issues in the group, as the stars to the bedrooms are quite steep - not an issue for us at all but it may be a consideration for some).