Artists drink wine. Red and cheap.
Eeschema has indeed been weird because it doesn’t have a normal concept of selecting objects. You can see that when you click with LMB a place where selection clarification is needed. You need to choose from the clarification menu which object you meant. But when you then choose an action - say, you press M for moving - you’ll get that clarification menu again! The object wasn’t actually selected at all, it’s just acted upon when you initiate an action. I have never understood why I get the clarification menu in the first place when I actually can’t select anything.
Arguably the biggest change for the future v6 from the viewpoint of an end user will be that the UI concept of eeschema will be like in all other programs – you can actually select things and see what you selected. It will cause some headache if you have already been accustomed to the current behavior, but the new system is worth de-learning and re-learning.
There’s also more customizability for mouse, touchpad etc. which will probably make working with different kind of hardware easier.
As was already said, you can test these with the nightly builds, with the risk of crashes, data loss etc. If you can do it, the developers might appreciate feedback especially about working with exotic HCI hardware because they can’t test everything themselves.