Druid Roots vs other roots

[MikeXG]

I've tried to do some testing on my own but my results are inconclusive - other than the DD portion of the druids root line, is there any other major differences? Looking at the best roots it seems they cap out at 3 minutes, casting time and mana cost aside, is there a difference? IE does one have less of a chance to break early? Even between the level 49 druid root and the 56 druid root is there a difference other than a bit more dmg, less mana and faster cast (not that those things are not awesome) Seems the druid root line breaks more often, could just be a "me thing".