I have both a Quickline and an Affinity X.
The Affinity X has a faster action than the Quickline by far.
Also I noticed the paint is very thick on the Quickline which IMHO equates to increased weight and loss of sensitivity.
You get what you pay for.

Also, note that the CTS MX series is no longer on their website, but I believe you can order it for an up-charge.
They offer the CTS Affinity M (Carbon Fly Rod Blank I Affinity M | CTS Fishing - Made in New Zealand) on their website which is more of a mid-flex profile; but again it's not the same as MX or as the X.