From the Crunchyroll comments and reading about Code Geass elsewhere, I've seen a lot of hate for Rolo and Nina. Honestly, they were fine. Rolo is even on the shortlist for favorite character (I haven't decided yet, it's between him, C.C., and Kallen). I know he did the bad thing, but he was still a compelling character. Nina did the bad thing too, but her biggest flaw is just that she's an idiot who seemingly couldn't comprehend that her big fancy bomb was, you know, a bomb. I'd have respected her as a character a lot more if she stayed deluded and crazy all the way to the end. Having her snap out of it so quickly just makes her seem like a moron.
I'm very much on board with the consensus that they both suck! Rolo was weird and annoying and then he killed Shirley, and Nina (in addition to being basically a nazi) sexually assaulted a table. I wasn't a fan of Suzaku either, but those two were way worse!