I finally got the motivation to level my shaman up to level 87, and decided to use ascendance. it was over way before I could finish looking at the model.
as a demo lock, maybe I'm biased about it, but ascendance is just too short to feel important. I mean, even back in WotLK and Cata, my metamorphosis was always something like 30-36 seconds, which is more than double ascendance. it feels to me that 30 seconds min should be the "standard super-transformation minimum duration"