I think that’s mostly due to the fact that it doesn’t use context menus and uses unintuitive shortcuts instead of being compatible with the standard ones. But yeah, this UI is sweet – would not object to the official animator looking like this.
I’ve been following development of this on twitter and it looks really awesome! If he can add tweening properties (brickcolor, for instance), changing Part0/Part1 mid-animation, and IK I’m going to consider trashing ScriptOn’s Animator v5.5.
Local rotation seems to be a bit broke. Still rotates around the original arm placement and rotation handles don’t snap to the part’s location. (Rotation parameter probably shouldn’t be exclusively regarding the handles.)