I've been reading up on exhaust configurations quite a bit... basically, i want to keep the "popping" from my exhaust (to me, it makes it sound more throatier), adding an X-pipe or H-pipe takes that away. My exhaust guy thinks that if i had a muffler, the loop will help with backflow and scavenging and help reduce the loudness slightly (depending on the size of the muffler).
On a side note, since separating my exhaust into two separate pipes, i've lost ~3mpg both hwy and in town... so, it's not for the weak pocketed.