I’m somewhat familiar with the Tennessee-Tombigbee waterway. That section of the Tennesse, probably the lower two thirds or so of the river, is mostly ponded behind dams with locks, barge traffic and minimal current. It also has more large pleasure boats than you would think because it is part of the Grand Loop.
The upper section has some serious TVA lakes too, and all the TVA lakes have power boats and house boats galore on nice summer weekends. There are a lot of better rivers out there to paddle.