Was a big fan of both the original film and the series. I agree that the post-series movies got worse as they went on. The show and the movies, though, were a labor of love by the creators and cast, and it showed.
As an interesting aside, some of the original "Slagtown" sequences from the movie were filmed on Western just south of Hollywood Boulevard in Hollywood and for many years afterward you could drive down there and see Newcomer script left on signs and walls. Some people didn't paint over it for ages!