I recently changed over to SEO Ultimate and so far so good.
I have a feature suggestion I think the developer should highly consider. Since I am new with this plugin I can't go back and add meta description and keywords to over 3000 posts so I think the plugin should allow auto-generation of meta description and meta keywords from information in the post.
For example, meta description takes first few sentences of a post and meta keywords can use the post's tags. Same thing for pages.
Feel free to share your thoughts and/or support this feature request. I think it would be very useful.