Interesting question Dave. I actually went to the Dava website after making that post and while they make a point of mentioning the different pick material, they don't speak much about gauges.
I'm actually familiar with the materials. The company I work for makes cable ties from these (and a few other) different material and they all have different physical properties. I'm not totally sure how that translates to guitar picks, but I do have my Dava favorites.
Sounds silly, but I really like the green one for my acoustic while I use the yellow for general work on my electric and the red for strictly lead work. I have notice that all of the picks respond differently to how much you "choke up" on them.
The main cause for my affection though, really is the fact that I seem to be able to hold on better to the pick as I'm playing