The GA machines are largely fine, and apart from the occasional misalignment issues, if they had options for Rovers/Rangers I'd be quite content.
However, over the last couple of years they have introduced a very irritating 'splash screen' that advertises using an app or similar nonsense, which I don't object to in and of itself, but the only way to dismiss it and get to the actual ticket buying is to press the screen - and this press is then transmitted to the ticket buying screen, which means you've probably now selected something you didn't intend to, requiring you to go back to the first screen. It's a rookie UI error to transmit the press across screens, and very annoying when you have to do unnecessary screen presses every time you use the machines.