The marker makes less noise, accuracy was improved, less CO2 is used, the longer 16" barrel makes aiming easier, rarely does any paint break in the barrel and should a ball break its really not hard to clean.
Kinda pricey and people tease me "could that barrel be any longer".
I use the all american 16" barrel on my tippmann 98. I own two 98s. I love PMI paint (marb or premium), but I have used other paint with great success. For 99 bucks I think the barrel is worth it. Go get one!