I've been an exclusive Tortex user for the past 4 or 5 years, mainly the purple but recently decided to try out some 'smaller' picks. I bought a couple of regular Jazz III's, a carbon fibre Jazz III, a Max Grip Jazz III and these Petrucci picks.
To perhaps cut a long story short, I really like the Petrucci picks and now using them over the Tortex which I have been using for years. It's only been a few weeks but I feel strange trying to use a Tortex now, they feel huge!
What I like most about the Petrucci is that they are a great middle ground between a jazz III for precision and fast picking and something which can be used still for strumming, as I found the Jazz III's weren't as versatile as I need them to be as they are so small.
The only downsides are that, although I understand the sleek black look of the pick is what Petrucci and his guitars etc seem to be about, I would have preferred them to be red, because as we all know, picks are easily lost! At least red or any other bright colour gives us half a chance of finding them again.
And secondly, more performance related, there have been a couple of times when I've been in the middle of performing a solo and the pick has got slippery under my fingers and takes me a few seconds to try and get it back under my grip, all the while still trying to carry on playing! Saying that, the JP raised logo on it works pretty well as grip under most conditions, just perhaps not as grippy as you might want it to be.
Definitely worth picking up a few to give them a try out at least.