I didn't really spend any time at all doing this. It took about an hour or so to fix the theme and then another couple of hours to write it up and take the screenshots.

If you really want to get down to semantics, tables should really only be used for tabular data. There are distinct disadvantages of using tables and one of them is pointed out above. The biggest problem I see is using structural elements for presentation so you can't easily change the layout without altering the (X)HTML. With something like Drupal where you can't just edit the source without overriding a theme function this becomes even more of an important issue.

Well, I actually use Safari 3 for my general browsing (it's very fast and clean) and only break out Firefox 2 when I need Firebug or the Web Developer Toolbar (there seem to be memory leak issues with Firefox). A bonus of using Safari is that form elements look great!