I take it you've noticed that Calix II is somewhat different than Calix.
IMHO, Nexy Calix is an excellent blade with unique properties. I've got both Calix and Calix II with the same rubbers, and can switch between each with very little adjustment. Short game and looping feel a bit better with the slower Calix, and blocking/driving/smashing are correspondingly a bit better with the faster Calix II. Dual impact is more pronounced with Calix, and less with Calix II, and because of that Calix II feels less special, almost like a Xiom V1 with a thin handle.
TLDR: If you were happy using Calix with celluloid balls, keep using it with plastic balls.