The new map viewer is nice but I have a very hard time with the visibility of the layer checkboxes. On the old map viewer, the tried and true simple checkbox design makes it very obvious if a layer is visible or not. Empty Box = invisible and Checked Box = visible
The new map viewer flips this. Now it's Greyed Out Eyeball = Invisible and No Eyeball = Visible. This is (to me) visually confusing and counterintuitive. It makes it difficult to know what layers I have checked at a glance.