@Tut: As you like to say, I disagree. @Zark raises an excellent point. The top navigation bar is very valuable UI real estate, and it’s put to poor use here. Manager is an excellent – even awesome – program, but there are a number of basic, universally accepted User Experience principles that are not adhered to in Manager’s user interface. Among these are the one that @Zark raises and the one that I raised in starting this thread: Functions that are most-frequently used should be accessible through a minimal number of clicks (optimally, one) on a control that is always visible (or at least always easily accessible) in an intuitive location and labeled in a semantically clear way. Conversely, functions that are rarely used should not clutter the interface but should be accessible through a subsidiary menu or other control.
I agree with @Zark, that the top-menu bar is rarely – or literally never – used. Some oft-used features on the left-side navigation bar scroll off the screen vertically at times (like the Summary tab) or, if too many tabs are activated, start off below the bottom of the screen (like the Settings tab and the Customize link). As for the metaphor of the left-side navigation bar representing tabs in a notebook, unfortunately the visual implementation doesn’t even make it clear that the navigation links are meant to be tabs so the metaphor doesn’t hold well for most users.
It’s little details like these (and like the upside-down triangle issue and the screen too wide issue, for example) that make the Manager UI look less polished. The feature set, the efficiency of the code, the price (free!), and most of all @Lubos’s dedication and commitment and customer-focus all make Manager a spectacular piece of work, for which I and so many of us are extremely grateful. Adding a little polish in the way of streamlining and perfecting the UI would improve the overall user experience and take Manager to the next level.