In the 30+ years that I have been playing the guitar, I have tried hundreds of picks. Choosing a pick is something very subjective and personal, both in terms of how it feels in your hand and how it sounds. As for the former, I won't say anything more than the fact that anyone who plays with regular-sized picks will need time to adjust to Jazz III picks (standard, not XL, which are larger). Personally, I have been playing with Jazz III picks for over 10 years.

I have bought and tried not only the Jazz III Ultex picks, but also several others of the same size from Dunlop. All the same size, all the same thickness. The shock was in the sound, personally I play 99% with clean sound. The Ultex picks had the fullest, most articulate sound, try them and judge for yourselves.

The only area where the Ultex picks fall behind the others I tried is in terms of how slippery they are. No, they are not as slippery as nylon or delrin picks, and the good thing about the Ultex picks is that as a material, it seems to have a tendency to "stick" to wet surfaces (e.g. when your fingers sweat, etc.). But still, the grip cannot be compared to the others that had a "rough" surface.