I have two pairs in patent leather and pvc, Bille et Boules and Debout 100 perpex, and they fit quite comfortable. No hardness, no squeakiness. For me, they seems to be the fastest to stretch but definitely not uncomfortable at all.The color is gorgeous! I think it's a bit much on an entire shoe, but I like it broken up here with PVC. I got these from Bergdorf Goodman.com but CL has them and I believe Nordstrom.com although size availability is decreasing!
They feel pretty comfortable, the PVC doesn't feel hard. Having said that, I have not worn them out yet; the weather is not cooperating… it may be a while. Squeakiness LOL, it could be a thing