I have noticed that the main menu on the left (Monitor, Content, Hosts…) opens up very quickly when you hover over it. I find that actually quite annoying because on many pages there is only little distance between controls and the menu, e.g. here:
The checkboxes are quite close to the menu. Due to that I often accidentally move my mouse briefly over the menu when I want to check some of those boxes. Immediately, the menu expands covering the checkbox I want to set. So I have to move right again, wait until the menu goes away again and then carefully approach again.
I think it would be much better, if there was a delay of at least 1s before expanding that menu to allow for briefly crossing the menu area without expanding.