I'd go with the CPs. I find them comfortable enough and flat foot bed allows for an insole if you need. Flat shoes are supposed to be better for your knees too. The uppers are stitched which would potentially make them last longer.
I had some GATs and ended up selling. They have some arch support but they weren't that comfortable.An aftermarket insole would be a lot better, but the shape of the foot bed doesnt allow it.