I ordered the 0.08", but I haven't actually measured it. I'm thinking about trying the 0.06" next time I order some, to see if it shows the outline of the blade shape better.
I think the thinner 0.060" kydex (I've tried 0.090") will give an easier release. That's my next kydex. I was initially worried about durability, but after heating and forming the thick stuff, I don't think that durability will be an issue with the thinner kydex.
