The dark/black wordpress bar that appears at the top of every page really interferes with viewing pages, and it wastes a lot of space since it's blank across most of the bar. It badly needs some tweaks to optimize it's usefulness and eliminate some problems.
When reading pages, if you use a page down command (e.g., hitting the space bar), the first sentence or two of the next page is buried under the wordpress bar -- forcing you to have to manually scroll to see those sentences. This is a distraction, and an irritating waste of time, especially if you read a lot and especially if you happen to read a lot on sites where the article or comments run for multiple full screens.
For users with small screen, such as typical laptops, that vertical space is prescious. As configured, the wordpress horizontal bar just wastes more of that space, when it's not even used that often relative to the amount of time the user spends reading various webpages.
Some sites neatly handle these problems by including a control icon on the bar that allows you to toggle between seeing the bar and eliminating all but the control button/icon. For example, see: http://www.cnet.com/ Their bar is at the bottom of the page with a control tab/button/icon to the right to close the bar, to the left to reopen it (personally I think it's more intuitive if the icon stays in the same place, ideally to the far right or left of the page, rather than moving). Or see: http://www.cbsnews.com/ which isn't the best example since their bar doesn't toggle, it just allows you to get rid of it entirely (bottom of page, control icon to the right). I've run across other extremely well known/heavily used sites with bar across the top or bottom that toggles, but don't recall exactly where offhand.
The bar space could also be far more useful and take a little less time to use if some of the options were spread across it in the blank area, rather than being drop down menus from items that are only on the leftmost and right most sides of the pages. Why waste all that blank space, when our most commonly used options could be directly accessible in it instead, with only one user action required instead of three (access drop down, move to selection, click selection)?