A friend and I do this a few times most years in kayaks. Water level varies a lot, gets too shallow to pass sections during periods of low rainfall. Some parts are leisurely, some can be challenging. Would not recommend using a canoe or tube, as I've seen both abandoned along the way. Sharp turns required. Someone has been clearing openings in the downed trees most years, but there will be 3-8 times you have to get past a log, and sometimes that requires getting out of the water. Going under or over can be dangerous if you mess up- careful not to tip and get pinned. It's unlikely, but the water's stronger than it looks, and you will tip if you try to pull up alongside a log perpendicular to the current. Paddling against the current is usually difficult and slow, sometimes impossible. 1 of the last ~7 trips we decided the water was too fast and high to allow safe maneuvering and recovery after tipping. Wear sunglasses, because you're going to get branches in the face. (and wear life jackets, obviously) Good amount of wildlife present, some good urban art- look back after going through the culverts.