I've been buying some older Fizik Arione CX variants lately. I cannot tell how things changed when Fizik went from the CX designation to the R-series.

Also, why do manufacturers have to change things. Many years ago, I bought a pair of Specialized BG-Pro shoes in a 44W. They were great. Then they tore. Specialized replaced them under warranty, but by then, they had redesigned the shoes, and they were different. I'm not sure how, but they weren't as comfortable.