Hmm, it was a bit of a surprise to me that Elvstrom was advocating Dacron..
Anyway, at this years IDM (international german championship) I think I counted three dacron jibs. The rest of the jibs and mainsails was Pentex. Some of the top ranked teams was there (Bundock, Gaebler, Polgar, Sachs..) and they all used Pentex jibs/mains. Cost is not a big issue to these guys, so if Dacron was better they would have used it. Especially since you only are allowed to measure in one set of sails for any event.
I have a Pentex mainsail on my Tornado, and are very pleased with it. I like it, especially when it really blows. In contrast, my Dacron jib is awful when it starts to blow. Also, I find Pentex sails to have better durability than Dacron sails. Going for a Pentex jib next season (and Pentex main + siliconised spi if my sponsor (wife) agrees

)!
I would stop worrying about the material (Pentex of course) and rather start evaluating sailmakers.
Did I mention that I like Pentex sails ??