Yeah was never much of a fan of "Slaughterhouse-Five" myself
Really glad I read "Cat's Cradle" first- otherwise, I might've assumed that Vonnegut simply isn't my cuppa tea. And while I understand its popularity, I think it's sort of a shame that it's his most popular because I'm sure it's turned off a lot of potential fans who chose it as their first Vonnegut due to its reputation. And the same is probably true- albeit to a lesser extent- with "Breakfast of Champions".
TBH it's been so long since I've read "Confederacy" that I don't really remember whether the black characters were really stereotypes although the fact that the main black character I remember was the janitor doesn't bode well. I just know that the sections of the book that focused on them were a chore to get through.