from someone who owned both, the actual Apexi N1 is really deep, doesn't drone, and is quiet when cruising with a steady foot on the accelerator. Light acceleration is deep and not raspy as well. The N1 is loud with aggressive acceleration and of course WOT.
The WS2 is almost always quiet, and just mellow at WOT similar to stock where you can hear more of the engine than the actual exhaust note.
I can't comment on other wanna be N1 "style" replica whatever type of exhausts from a personal stand point, but i've never heard one that even sounded like either of the Apexi versions, N1 or street muffler. They've always been louder or loud and raspy.