^ the one thing is dislike about Di2 is that you can mistake the up for the down.

And they're backwards from left to right. There was a physical reason that cable actuated derailleurs work like that. But now the shift "levers" are just switches.

You can make them do whatever you want, (and you can reprogram Di2) but Shimano is still just aping mechanical shifting instead of making the best interface for an electrical system.