I think previous posters have covered the issues. (My personal opinion, for what it's worth, is that top-tier on one airline is better than a bottom and a mid.)

However, we ought to be careful about the terms we use. There is no industry standard for equating precious metals to status levels. Gold, for example, is bottom-tier on AA, mid on Delta, top on BA, nonexistent at United. The assumption that everyone shares a particular poster's concept of what "gold" corresponds to is dangerous. Unless we're posting in a specific program's forum, where we can assume that program's context and those who read posts there will understand it, we should define our terms or stick to generic ones like "top-tier."

End of lecture, off soapbox. And now back to our regularly scheduled programming...