Rated 5 out of 5 stars
An excellent and practical dark theme, with very cute artistic touches.I especially like how it sets the content area of new tabs to black. I've always found it rather jarring when you're using a dark theme, open a new tab, and are suddenly blasted with a white screen.
My only possible complaint is the large, bright icon it adds in the center of FF's Downloads window, which makes it hard to see some of the (also light color) figures on the current downloads. Maybe this can be improved...?
UPDATE: HDI works just fine with FF 22.0. I've installed the Nightly Tester Tools add-on (available here) which adds a "Force Addon Compatibility" command that lets you re-enable HDI—and I've no problems with it at all. So if you can't live without HDI till Aatif has a chance to update it, there's the solution!In many cases, declaring an existing theme or extension "compatible" with a new FF version is just a formality. The FF team has high standards, though, and they like to be sure there are no significant problems. If you use NTT to enable anything else that hasn't been certified for a new FF version, just keep your eyes open and be careful—you're being a "tester"!