Am having this issue since day 1, I have updated to iOS9.0 on iPhone6. Initially I thought it must be only with my device, then came my new iphone6S+, migrated the data on to it and i see the same issue on 6s+ too.
I waited for 9.1, hoping this issue would be addressed and resolved, the issue still existed...then 9.1.1, the same case, still no luck
Today updated to 9,2, still facing the issue. After today's update, i am infact facing this issue more frequentl, than the previous upgrades, earlier the frequency was once in 2-3 days, now it's resurfaces with an hour with iOS9.2. In the past 5 hrs after upgrade to iOS9.2, i have restarted my device more than 5 time to get rid of this issue. I am tired. I don't think apple has any clues about this issue or this issue is not impacting bigger group of audeience and is being treated as a low priority issue.
This issue is very irritating and disabled the animations. Every thing becomes superfast.
Apple, have a look into this issue at the earliest.