Feedback on Playback

When I enter notes or playback a score, there is very bad feedback and lagging. Exported mp3 does not have problem. Older versions of MuseScore were also fine. So I do not believe it's problem with my computer or loudspeakers.

I also do not like that "page down" doesn't go to the next page now and editing the "instruments" seems to be more complicated. The tab doesn't always appear and it always took me a lot of fiddling around to find it. The left panel is taking up too much space so that the whole app needs more than 1/2 of my screen. This is annoying when I have to refer to another app to input my notes.

On the whole, as of now, I do not like version 4 at all.