I believe when you buy a signature model of something, the main reason is 'cause you at least admire that one person.
In my case Petrucci is one of my all time favorite guitarist and I thought his picks must have been pretty good.
I'm not at all surprised that my thoughts were confermed since the first time I used one.
The grip it's simply fantastic and the very tip of the pick is smoother than any other pick I used, giving this Dunlop JP an edge over many other pick particularly if you play fast, the pick almost glides over the strings, awesome!
I need to say that the tone that comes out is more full and solid than most picks and if you like a small but durable and fast pick, I strongly recommend this one.
Of course it's more suitable if you play metal or hard rock perhaps, but still it's very versatile for other styles.
The only flaw I found is that it's dimention doesn't make it suitable for playing for example punk rock fast stum patterns as it's like it's gonna slip out of your fingers.
Other than that for the price I suggest to buy one pack and try it anyway!