Honestly, I prefer the looks of a 4-1. I just don't like how loud they are. I've never heard any other Nighthawk long enough to make judgement, but I feel the 650 sounds just right. It's quiet enough to not be annoying, but it really screams when opened up and has a beautiful, understated burble when engine braking. I like the tone too. The 4-1 systems seem to me to be too loud and don't seem to sound as good, but that could just be due to the fact that most people take these videos with their cell phones and then post to youtube, giving poor sound quality.
Also, I think that is member nhk750's bike. He just finished a thorough restoration and cleanup and installed that 4-1.
I always thought it was funny that if you bought a car or truck with single exhaust you change it to dual, but for some reason its different on a motorcyle
The only good reason to have a dual exhaust system on a car is if you can't snake a suitably sized single pipe through the undercarriage. Anything else is just for tone or appearances. Single exhausts make more power - there's a reason many dual exhaust systems have a X/H pipe crossover to link the two banks of cylinders.
