2018.3 hierarchy UI mouse cursor highlight lags several frames behind the actual cursor. If you move the cursor over the hierarchy up/down somewhat quickly you'll see the highlight is usually about 1 gameobject entry behind. It makes navigating the hierarchy with a mouse feel heavy and increases mental load and fatigue. It's like playing a laggy online game that doesn't do actions in real time. Please make the cursor highlight not lag or give the option to disable it. This might seem like a trivial thing, but is surprisingly annoying when it's one of the most core things every single user will see and do every day and every time. I tried to get used to it for 4 beta versions and it still annoys me every time I try to pick something in the hierarchy. My computer can handle the editor fine and it's not a performance problem.