I have been using Jazz III picks of various kinds for the last 5 years or so and have tried most of the variations (Red, Black, Eric Johnson, John Petrucci, Ultex, Maxgrip, XL).
Up to this point, I had been using either the Eric Johnson or Ultex version but thought I would try something different. I like the shape and size of these tortex picks, but the edge geometry of them has sent me back to my usual Ultex. Compared to a standard Jazz III, the tortex version has a very square edge, not bevelled as the rest of the range. I have become very accustomed to the feel and tone of the Ultex bevelled edge, and these tortex don't give you as smooth an attack as with the bevelled edge. I also miss the raised lettering of the other models, as the smooth surface of the tortex doesn't offer as good a grip - they feel slightly slick in my fingers.
Overall a quality plectrum, but just not right for me.