Every little bit of it. I don't want to start a culture war here but I think GP-Pro EX software is on par with any major player in the field. And I don't think there are many brands out there that can beat G3000/4000 series slim form factor. And not many other brands can boast such large range of supported PLCs and other devices to communicate with.
If you are currently at QuickPanel/Total Control stage, go for Pro-face and never look back. There will be some quirks and thing to learn but in the end you will appreciate it.