Soap recasts aren't rare. Mostly the case is that one is far better than the other. E.g. Jacqueline Jossa is far superior to Madeline Duggan as Lauren Branning, or Kim Medcalf was a way better Sam Mitchell.

Are there many examples of characters who were enjoyable no matter who played them?

Most recent ones for me are Lucy Beale - I liked both Melissa Suffield and Hetti Bywater though I know a lot of people didn't rate Hetti much as an actor. Also Shabnam Masood. At first I wanted Zahra Ahmadi to return but in recent months Rakhee Thakrar has completely won me over. She's a character who has changed a lot but someone I like played by both the original and current actresses.

Any others?