I'm having the same issue. I can tweak my settings in Skype and they stick and look nice while in Skype. As soon as I start up OBS, it seems to revert back to defaults and looks choppy/like crap.
Edit - I got it working! The trick that worked for me was to configure the camera, hit OK, then hit Cancel on the Webcam properties screen.
Edit to my edit - It doesn't stick apparently. Re-starting the preview shows it back to default settings. Have to do this workaround every time I want to stream, apparently. A minor annoyance.