I notice that Showtime plays this movie quite often...and I usually watch part of it when it comes on. I just watched the end of it. I have to admit, it is pretty watchable. My favorite Bill Cosby moments were always when he would get silly, and this has plenty of that. For a comparison, put this movie next to another notoriously reviled movie: Megaforce. Megaforce has some hilarious moments (motorbikes that launch rockets, and spectacularly laughable special effects) however the rest of the movie is painfully drawn out and could be edited down to about a half hour if they took out what doesn't work. I would say that in comparison to Megaforce, Leonard Part 6 is veritable tour de force.
Review of Leonard Part 6
