Right from version 8.x I have always had a challenge using the WordPress editor.
1- The biggest irritant i noticed is that when in short box view I am not able to stay scrolled down. In less than second after I scroll down I am taken right back to the top of the box even though the cursor continues to stay where I placed it.
2- I can maximize the editor only in the 'envisual' view but not the 'html' vie.
3- This is definitely not a WSYWIG editor. It looks one way while typing and another way when previewed or published. Believe me this one bug has made me waste many many hours trying to get the look just right.