It may look functional but it causes everything on the page to slow down as more changes are made to ngModel. For example if you log some events on Draggable, you'll see many new draggables are created very quickly and many duplicate events triggered as you interact with the slider.
The design seems to be to create a new jQuery plugin every time ngModel changes:
https://github.com/darul75/ng-slider/blob/1b14a171217df22a4e857fe1449b71077cc5ac4e/src/ng-slider.js#L53
It may look functional but it causes everything on the page to slow down as more changes are made to ngModel. For example if you log some events on Draggable, you'll see many new draggables are created very quickly and many duplicate events triggered as you interact with the slider.