Kharma Ceramique questions

I am hoping someone can help me with some questions I have on the Kharma Ceramique speaker line. I have seen some of the older model, 1.0, 2.0 and 3.0, Ceramique being sold for very good prices. How do the current models 1.1, 2.2 and 3.1’s differ in performance to the older models? Has anyone compared the 1.1, 2.2 and the 3.1 to the 1.2, 2.3 and the 3.2’s? Are they worth the extra money?

Thank you for your help
Brad Fisher