Which Saddle?

For me yes. I thought I'd try the px to see if I liked the shape – then buy the fizik. The shape is very similar but the support of the fizik is much better. My planet x saddle had just a small amount of sag in the middle which was not good. The fizik only flexes under your thighs.

Very similar experience for me. I was fairly happy with the PX for quite a while ('000s miles) and only switched to the Arione when I notice a proper bit of sag in the middle. The Arione immediately felt like it was providing the right amount of support / flex where needed and a few hundred miles later just feels like it's made of sterner stuff. I don't really understand all the different rail material options but I bagged a basic model of t'bay for £50, very happy with it.