My opinion is that the in-camera stabilization is rather good. I usually am the kind of shooter who doesn't ever like to have OIS on while I'm shooting, but with the Dvx200 I find myself utilitizing that feature more often. I can't speak to warp stabilizer, as I've never used it.
The OIS is fine. For travelling/walking shots, the OIS makes the image look like it's coming from a heavier camera. Yes, it bounces, but it looks like bounce from a hand-held full-size ENG camera with a heavy Hytron battery. It's very good.