[paulygates]

I use Dunlop Delrin 500 1.5 mostly. I don't like my picks to flex as you can get a good dynamic range just by how hard you hit the strings. Sometimes I use a 3mm Stubby which are really good for fast alternate picking and make it really easy to squeeze out harmonics.

I don't know if size affects tone. The tortex picks give quite a hard attack so I guess the material must affect tone. I never liked the texture of tortex but I find the delrin is a nice slippery material so you can play quite fast.