I had the original Vespa exhaust installed from the beginning (so I have no real comparison to the original exhaust).
I like the sound, even on longer journeys it doesn't bother me.
Please note: although it is manufactured by Arrow, it is not identical to the Arrow exhaust for the E5 Vespa.
There is a software update available from Vespa for the Vespa-branded exhaust. To have this installed by a Vespa dealer, the dealer needs a code for the activation. If the exhaust is ordered from an aftermarket dealer, this code is missing. Do I need this software update? Probably not, it was important to me personally, so I had it installed directly by the dealer. I also received a printout from PADS that the update had been installed.
See also:
GTV300 2023 doesn't fit Vespa Sport Exhaust