This is the reason why I don't use Chrome myself. I want the tabs where they make sense from a design perspective next to the web page itself. The tab should be attached to the page itself. I don't want the URL bar in the way.
The content of the URL field is dependent on the tab. It arguably makes far more sense to have this strong relationship represented by containing the URL field in the tab itself rather than having a global URL field in one part of the window with content that changes as different tabs are selected in another part of the window.
That makes sense, however, I don't spend time looking at the URL. I look at the tab titles much more than I ever look at URL's. Additionally, to the common user the URL is a mysterious, meaningless thing anyway. They are more concerned with what the title of the page is.
Having to look over and past the URL bar to see what the title is, or having to look over the URL bar to select a tab, then back down past the URL bar to the page is less efficient visually.
I'm sure there are pros to the tab placement in Chrome, just as there are cons. Personally, it just isn't for me.
This stops making design sense when the tab bar (which shows info for many pages at once) is sandwiched between the window title and the address bar (which show info for exactly one page at a time). You go from specific to general then back to specific again.
I wish I were on my desktop, but maybe someone else can give you a link to it.... but the Mozilla team put together a presentation why it makes sense in every aspect of the experience for the tabs to be on top, least of which is because it preserves context. You change the tab on the top, it changes the url bar below it, and the content below it.
It's true that tabs on top are more sensible structurally, but they fail in one big way: there's no place on the screen that shows the full page title. I look at my Chrome, and the titles in the tabs are all truncated. I go to FF, and the title of the current tab is in the window's title bar.
