after i read threads talking about Xpipe vs Hpipe .. i found this :
Xpipe works better if u want to go for high preformance or stroker like supercharge cams..
Hpipe works better if ur target is just headers and CAI..
and if u go with xpipe and u only have stock engine with headers u gonna lose the prusser frome the engine and the Hpipe doing well and good prusser for u with stock engine..
found this can help :
http://youtu.be/Y0Va3sDhqwI
i have magnaflow catback xpipe and the sound is very deep , that not mean the magnaflow is bad ; personally magna is best soud i found and it's gives nice tone with a headers..
sorry if my explaning is not very clear