The reason I asked was that a friend borrow an old Max 2603 (I think) pipe of me, but this we couldn't find so he asked if I would take the 2615 pipe in return.
I got it yesterday and will test it soon, it looks short so I guess it's more of a top end pipe.
Take the 2615. I have tested extensively and this is by far the best Max exhaust yet. They worked very hard on this and Fantini has his own Homologation for it. Be sure to get the matching conical manifold as they are meant to be used together.