Hello and welcome!Your questions are exactly the same as mine, a few months ago.I traded several emails with David from Larini to find out what i really wanted. My question was , X or H pipe?Definately would go for the X, because it would give a noticable but NOT loud volume change.What could more hear was a change in tone.
BUT
avid told me that if i was someday going to replace my rear boxes, the sound (with the X) would be a lot louder than with the H.
I don't think i'm going to replace the boxes, so i chose the X. Later on, i bought a set of front sports cats, and together with the X, i have the sound and performance i wanted.Sometimes i want it to be louder in normal drive only, but once i floor it, anything is history.
Hope this helps,
Nikos