@Meddler: What are your thoughts on CC that breaks when you attack?

To put it in perspective, here's an example:

#Ensnare Fires a skill-shot that roots the first enemy it hits for an extended time. Attacking the rooted target consumes the root to deal strong bonus damage. (Allied attacks do not trigger the secondary effect.

Why this? It allows interesting playmaking decisions. Do you leave the snare on to keep your target from moving, or do you just go immediately for the burst damage? At what time do you strike?

Good or bad concept?