We were there late in the season after coming down the Rideau. It was a week's wait until a good weather window opened to cross to Oswego, but Kingston and this marina worked out very well. Since it was late, there was plenty of room for berthing. All the marina's shoreside amenities were very good indeed, with clean bathrooms and showers, and new washers and driers. Kingston is a nice city with plenty of restaurants and shopping.
Note: it is very exposed to wind from the north, east, and south. We were pinned pretty hard to our facing dock for several days, though when our day to leave approached we were able to maneuver off. Perhaps the lesson is if you can't get off your dock due to high winds, it's probably better to stay put.
All in all a good stay.