Greg I understand where JTgofish is comming from. Look at B&W, they pump their Kevlar material as being something really special and unique, Which it is, and the give it a yellow color for added eye catching feature. Good and fine. But how is the other construction, the internal mechanics of the driver, voicing the lower midrange fq's. Personally its not my cup of tea on my JADIS ORCH REFER, a amp well known for its purity on midrange. I bought the 602's cause the wife got sucked in by the salesman.
I had paper cones in the 70's and my speaker for 20 yrs was a pair of philips 2 ways, served me fine in the bass until I came across my currect speaker. I know all sorts of poly cones over the past 30+ yrs, not a one I like.
The only material that i came across that competes with my currect sopeakers magniesum material was the Cabasse with its white foam material. But the Excel has the Cabasse beat in the bass and also the internal voicing from the "motor" of the lower midrange fq's.
So Jtgofish is right, some labs will come out with a marketing ploy to try to convince you "our new spaceage materail is something unique and like nothing you ever heard in your life". Gimmicks are a part of this trade. Cone material is only one part of the speaker, how all the other parts come together give the driver its particular voicing, its nuances and "flavor". Someone mentioned the old cliche "no driver is perfect sound" well obviously we all know that a live orchestra/jazz band is one thing, our speakers will have limitations. But we strive to get as close to original as possible. Some are closer, others are further away. Some like thise music to sound one way, others another. I've beenb seeking 30 yrs for what I hear in the Excel. Others prefer Vandersteen's sound. And so on....