Usually, one of the surest signs of decline in a series of any kind, be it TV, book, or (usually original) movie, is when its creator ceases to have direct involvement in it. Has a series of any sort ever maintained or increased its quality after such a departure? Only caveat: the series must’ve been good in the first place. Otherwise it becomes a different question, in my mind.
That’s kind of tough to say. Gene Roddenberry wasn’t as involved in Star Trek II: The Wrath of Khan and I think it was a better movie for it. I think he said it was too militaristic though I can’t back that up. I don’t think he was all that much involved in Deep Space Nine and that series was a bit better than TNG.
Marc
Opinions may vary, but I would vote that Pink Floyd was better under Roger Waters than Syd Barret.