Nothing, this grip and the hoses make your Tippmann unbelievable, I may even say it is more like an autococker now.
Tippmann 98 Custom with two piece Mako Ultra Barrel, and some Dye Stickies, with an expansion chamber.
Whats there to say but everything? It makes your gun fire very straight, more shots per tank, less velocity needed, SO consistent, comfortable, nice price, just a great product overall and the chamber makes the gun look kinda suite.
Nothing really, if you enjoy your handle just learn to say goodbye, I know I had to, but it was beyond worth it, Beyond.
I suggest that instead of a new barrel get this upgrade first, great design, great use, wait till you see it put enough power to shoot right through bushes, oh man its nuts, just believe me and buy it like right away, beyond the beyond of value.