Can't speak for the USB video transfer device, but I use Pinnacle Studio 8 video editing software, which comes bundled with the Studio Moviebox. (Transfer movies from my digital camcorder using firewire)
Studio 8 is pretty good, and is intuitive to use without being patronising (can't think of a better word, but some other systems seem this way!).
Is it the best? The only criticisms I have are the occasional need to reinstall to get it to work properly - dont know why this problem occurred, maybe nothing to do with Studio 8 - and I find creating bespoke DVD menus quite hard (although using the default ones supplied is easy)