Not sure about DVD video, but PowerISO is a pretty good program. And Nero is a great program, if you know how to wield it. If you get version 7.0 or so, it should run perfectly fine. The current 8.0 program is a bit much.
With nero you really don't need everything that they give you. You can remove most of their "editors" and use a better-quality video editor. I typically just install the Nero Burning Rom and that's it. Nothing else that isn't required for that to run. My system stays quick and Nero runs like a champ.