I do and I really enjoy it. There's a "social networking" component that makes it interesting and that helps produce income. I like the format of HubPages more, but unless you're pretty tech savvy, you won't get many people to read your hubs.
Bubblews is a community where members interact, as well as write short articles. For me, that's a winning combination, although I would like to write longer, more detailed articles. I think long articles challenge the attention span of most Bubblews activists, so I keep them short....around 400-450 words. My typical hub is almost 3 times that length.