How "rough?" Like PS3 jaggy territory?
Eh, worse. Even on my Rift, lines can look really crappy. The difference though, is that what you're seeing has depth and therefore realism that no tv/monitor can duplicate, so it's very much a give and take.
It also really depends on how the game is designed. There are some games where you can barely notice jaggies for whatever reason, I don't know if it's the contrast, artstyle or some other trick (yes I know about AA but that doesn't always seem to be the main factor), but it's definitely possible to mitigate the ugliness of it. Project Cars looks terrible on the Oculus to me.