I’ve got a Gemini on my mkII Nismo and it’s definitely loader than stock having put 1,000 or so miles on it. It’s at its loudest at 3k revs under load but no drone. Quiet enough on the motorway. I’m planning to add some sports cats next year and that will probably do me as I don’t want it too loud.
Good quality exhaust though and very happy with my purchase.
I would also add sound / volume is very subjective, so if you’re unsure, pop along to one of the arranged meets and I’m sure plenty of folks will happily fire up their car for you to hear.