How could caramel BC and red velvet cake be gross? It's a (faintly) chocolate cake. Chocolate and caramel go great together. Some exclaimations of eeeew I can totally jive with, but chocolate and caramel? Say it ain't so!!
I find that there are two basic camps in the RV filling debate. Cream cheese or just good ole vanilla BC. I think it depends on what you grew up with. I think both are good, but the tang of cream cheese is really good with the subtle cocoa flavor of the RV cake.
And I don't know... I like chocolate zucchini bread... chocolate and carrot cake might not be all that horrid together. Kind of like chocolate chips in an oatmeal cookie.