In any fan forum, discussion can often devolve into "aren't they great!"-type inanity. We're all fans, so obviously we think they're great.
What about their weaknesses? What they don't do so well? Please don't flame me, but I will start out with Mel Blanc. He is one of my Top 5 favorite cast members (maybe even Top 3), but even he aint poifect. Truly one of the all time masters of voice characterization, there's one key area within that domain where, IMHO, he was asked to deliver many times but didn't come through: accents, or more specifically, foreign accents (his regional US accents were great, and he set the standard for Brooklyn accents).
Mel's French accent was just about passable -- Professor LeBlanc was not my favorite character, but he did an OK job with the accent (and when he played French waiters). His Mexican accent was OK, I guess. But whevever he was asked to do an English, Scottish, Irish or German accent -- OMG (as my daughter says) -- it could be TERRIBLE.
Now, Dennis Day on the other hand did a fine English accent and a very good German one - why wasn't he drafted to do those roles? (Dennis's Irish accent was effortless, but a little bit "stage Irish")
Anyway, I've rambled, and not to pick on Mel Blanc. ANyone interested in a discussion of cast members various strengths AND weaknesses?