This is absolutely THE place for your stay in Quebec City.
Location: Close to the Old Quebec, walking distance to downtown, Plain of Abraham, Parliament, etc., 800/801 bus stations are 2 minutes away, which could bring you everywhere around Quebec City, even beyond tourism attractions. The public transit in Quebec City is surprisingly good for a North American city, and it is within your reach from Sylvain's place.
The Unit: The spacious apartment (yes, it is actually more spacious than in the photos) has two bedrooms in the basement level, kitchen and living room on the ground level. You'll find everything you need here, including a full suite of kitchenware and other tools for even month-long stays. Before our arrival, we communicated with Sylvain regarding our concerns of Internet connection quality as we would need to work remotely a lot. Sylvain was very kind to upgrade both the connection speed and WiFi router for whole-unit coverage. It's perfect!
The Host: Sylvain is among the top hosts of Airbnb. He's always responsive of our questions, and is extremely helpful when we had minor issues. He really cares about his guests.