I've heard a number of times that thin picks gave more attack but I haven't figured out why - I would think that with a stiff pick more of the force you actually put on the pick goes to the string, and sharper tips put more pressure on a smaller part of the string, allowing for more of your effort to translate to attack (only going by physics equations on elastic collisions and imparted pressure). I can never tell the difference between a moderate and a hard hit with a flexible pick because so much is lost to the pick bending.
The main reason for my use of Jazz IIIs and filed-down (sharpened) 1.5mm nylons is that they let me beat all fuck out of my strings. My tone in a lot of ways revolves around how much more 'metal' a hard-hit thick string sounds; it seems more full and chunky than a little poke with a potato chip (for some general idea of how hard I play rhythm, on my 7-string, tuned down to Bb, I was stuck with 10-56 strings for a while and if I wasn't careful to limit my attack the low Bb would go up a whole tone - I sounded like a fucking pogo stick! - and now even with a .68 I can hit a little too hard and make some riffs sound out of tune) and when I switched from Tortex 88s (which I used for the first year and a half of my playing) to Jazz IIIs and 1.5mm nylons I was able to hit much harder and with better timing.
Steve (and all other thinner-pick users), how much force can you actually put on a string before you lose additional thwack to the pick's flex? I've used thinner picks for clean strummed passages and tried to give them another chance for some Nevermore stuff after I found that you used tortex 88s, but I couldn't keep them from bending and throwing off my attack and timing (I have one that's still a bit bent from down-picking thrash stuff). I also notice that, at least in the Psalm of Lydia where you and Loomis went at it one after the other, your solos seemed a bit more legato-oriented in the faster runs and Loomis machine-gunned the fuck out of his stuff - how do the picks' attack compare with your legato (do they 'fit', as far as dynamics, with the volume of your hammered and pulled-off notes?) and when you switched did you need to readjust your pick attack in the solos to keep the legato notes from seeming too quiet?
Hmm, too many questions, not enough time. Oh well.
Jeff