Hello Susan, this post has been here a while but I am finally sitting down to respond to it. My comments are similar to some of my previous posts.
I think Summer Wine is unique in that its' inevitable character changes actually worked for the benefit of the show.
I enjoy the different characteristics of Foggy (his character was even a little different in his second time around), Seymour and Trully. When I watch the show from beginning to end I enjoy the Blamire years, but then it is exciting to see Foggy again (afterall, at that point I haven't seen him in rotation since approx. the 1998 era). Then it is great to see Seymour again (especially because his first few episodes are among my favorites). Then it is good to see Foggy again (especially because Series 12 might be the best). Then, since I started watching the show during the Trully years, it is great to see him again because ultimately, the era of Trully, Clegg, Billy, Alvin, Smiler, Tom, etc, running around is the show I started with.
I can''t say who I like best among Foggy, Seymour, and Trully, but I certainlylove the variety. As some members put it in previous discussions, the changes in the third man gave Clarke and Bell more material to work with over time.