The new functions are fine but I miss the one hand, one click +/- and the one click % drop down menu of the old version. Find a way to restore the functionality of the old version and you get five stars.
With the new Firefox WebExtensions API's, it is not possible for an add-on to have more than one toolbar button, which prevents separate +/- and dropdown buttons.
There are of course the Ctrl+0, Ctrl+- and Ctrl++ keyboard shortcuts.
