Ive read feenys book also, and in general I think betting the river is correct If I feel I can safely fold to a checkraise. However, Lets say you always bet this board with your set and you always called a checkraise no matter who your opponent was. Even in this case I believe that betting is still +ev versus checking since the vast majority of the time when an opponent checks this board they do not have the straight, and you get to pick up an extra big bet. I still may check this board against a strong player or a player that loves to checkraise.