First of all, I understand change is sometimes hard for people to accept. That being said there are a few things about the interface upgrade that are issues.
First, when purchasing a ticket to a new gate, it isn't apparent the ticket has been purchased.
Second, the screen doesn't scale to my computers display. This means I have to scroll to see the X to exit a particular screen.
I have to scroll down to see the "areas" option to access other areas. Most of the other stuff is just a matter of learning the new interface.