I’ve personally opted for the Akra. Not really louder but it gives a deeper tone to the bike. It’s still a bit muffled full throttle. I’m also gonna go for the cat delete to free up the sound a bit more without going no db-killer.
IMO not exactly worth the 600€ asked for the Akra but the built quality is very gweeed. I’m also thinking resale value for the bike when the day arrives. I can’t speak for the other brands though, I almost went to the LV-10 from Leo Vince but the racy only use put me off.