As you can see flying around anywhere in the nether also tried the overworld will result in fps drop with sprint and or just plain flying. Normally my fps is around 109-155 when flying with the standard resolution in the update my fps went down to 30.

My setting to reproduce it:
1.standard args standard options go into a standard world
2. fly around in default resolution fps drops

possible solutions for mojang to make:
1. lower the quality of the resolution when flying slighlty maybe just to 1.8.1 stats when flying
2. Don't render everything when moving/flying fast just simulate blocks/have a blur
3. have a lower quality minimaps like console did but, I would recommend 1 or maybe 2