I think Paul Reubens as Troy Stevens was bad because it was evident that he was a character. I can't think of any game show where the host is clearly portraying a character worked. It was almost like watching a bad SNL skit instead of a real game show.
I disagree with whomever said Bill was miscast for PW+. I thought he did very well. It was also nice to see Bill's unique style blend in quite nicely with the format. As for TJW, he was a bit slow. Jack Barry ran the show at a brisk pace, even in the show's later years, so for the fans to suddenly see the pacing change might've been a turn off. Some of us know the story of when Jim Peck filled in for Bill Cullen. Jim ran the show as fast as Jack Barry used to, and they had to stop tape because they ran out of questions! The producers were used to Bill's pacing at that point.
Lynn Swann was fine on TTTT. I think he was only meant as a temporary replacement until another host could be found. Lynn was on the panel from time to time in the 1990 run, so he already knew the game.
Also, while I agree that Rolf and Michael Reilly were not the best choices to host their shows, I didn't have any problem with Ty Treadway on Merv Griffin's Crosswords. Was Merv really THAT involved with the show? His health was quite poor then, and I think he died before the show premiered on TV.
I think Ty was one of those hosts that just played the game, but added little to nothing personality-wise. I think Crossword's major problem was with the spoilers. It just seemed unfair that the two front players could accumulate all the money solving many words, then one of the spoilers takes all that money by only solving ONE word.