Just upgraded from latest 6.5 to 6.6.7. IT was quite a shock, I thought I broke the update partially.
The black colour isn't appealing. I would prefer if the header bgcolor was still mainly white. The main menu items (Dashboard, Main, etc.) feels like it's together in it's own space at the top (black bg). No one will associate those menu items with the bottom section at all. It's totally disjointed with the white space with information. I would either change it back so that the menu items are actually prominent again, or make it a tab-like so that each selected menu item is visually 'together' with the info below. Not sure if that make sense.
Azure is almost great for the content wise, except that the menu items are on the left. Either an option to keep the text expanded, or (which i prefer) move it to horizontal placement (follow 6.5's style).
Alternative colour schemes (which doesn't change the layout) would be great - bright/dark themes.
The display settings section is also confusing, it should be separated into Layout and Themes (and another for Misc like date format etc.). Lots of options, no photo/instant preview. People can select their preferred layout (displayed first at the top), then play with themes (second to be displayed), then misc. display settings like "Show array utilization indicator" or "Show banner" etc.