I've been playing guitar for 22 years now. For at least 20 of those years, I've been using Tortex picks, and I will never stop using them as long as I live.
I tried all of the thicknesses over the course of a few months. When I started, I was playing Ramones style punk; strumming barre chords all day like they were going out of style. It seemed to make sense at the time to use the thinner picks, the .5mm or .6mm. (I think these were the red and the orange ones...) They were totally flexible. The red one barely registered at all, it might as well have been a little piece of tissue paper. But at the time it made sense to my dumbass 16 year old neophyte self.
A little later, I discovered the joys of speed metal. I began picking and peddaling on individual strings rather than just strumming chords. This was when I started experimenting with the thicker picks. .88mm, 1.0, 1.14. These would be the green, purple, and blue ones. Eventually I settled on the green .88mm and I've been using them ever since. I can't even imagine using a different pick anymore.
The reason that I fell in love with these picks is that their edges aren't rounded like standard "Fender" style plastic or tortoise shell picks. The edge of a Tortex is cut at right angles, they have corners. When you peddal on a wound string, you get an amazingly crisp and sharp scraping timbre that just can't be achieved with standard rounded off picks. The catch is that of course the cornered edge wears down rather quickly as you play. You will only get this awesome sound for a few minutes. A professional performer would want to switch to a fresh pick at the beginning of each song. A bedroom virtuoso will get more use out of them.