Looking around with mouse is not smooth anymore, like it was in 1.2.16.
Despite much better framerates, it feels like there is a crude mouse acceleration implemented. It is evident when zoomed in. Slow panning don't follow the speed of mouse moves. It feels like there is a threshold of speed above which the mouse pans the view very fast and below which the panning becomes very imprecise and slow.
ETA:
It seems there's a deadzone or a filter in place. Mouse movements below certain threshold are ignored. This makes slow panning on large zoom choppy and imprecise. A regression from 1.2.16 implementation, in my opinion.