TBH there are quite a few unheard of / underplayed exhausts for the Z.
For example this
Is an amazing sound. I like it far better than any exhaust i've heard for the Z, throaty and friggin deep, man. Half the forum doesn't even know of its existence, and lots discredit it for its lower price tag (can be had for like $500 new, shipped). I have it and i'm stupendously in love with it.
Go with whatever the heck you like and dont worry about the rest. Youll be driving it nobody else.