Image quality are not really superior to the viofo cameras as i understand it, superior to me is a lot better, and i am not sure i cold tell the 2 apart in a double blind test ( also i never ran the 2 head to head as i never had a viofo camera )
If i could it would probably be differences in camera field of view that gave it away VS image quality.
But i think SG spend a little more on some of the hardware like lens and so on, and they do set the high standard for customer care and service.
Viofo also have reputable resellers in the US, so from a consumer standpoint you should also be good with them. like with SG if you go to their own store you will also save the Amazon fee, which there are no reason to pay if you can avoid it, Jeff Bezos got enough money as it is.
I am as i mentioned associated with SG as they often send me free cameras to beat on, so some bias i assume there is whether or not one try to look aside for such things.
And as their stuff have always just worked for me i am of course happy about it, the only problems i had was the very first camera from SG back in 2013 the lens slipped out of focus but i adjusted that myself, and in the 2017 batch of 3 cameras the SGGCX2 camera after a few months it somehow backed itself into a corner, but loading the same firmware again fixed that up permanently, o and then i am one of the very few that have gotten a faulty GPS antenna, but that one i just swapped out with a older one i had lying around.
Fortunately people don't have to take my word for anything in regard to SG, a look around these forums and elsewhere i assume can attest to their work.
A few months ago i donated the 2017 SGGCX2 to a friend of my nephew, and the kid is very happy about his nice free camera, and i also don't hear any complaints from my friend that have the V3 version of the SGGC9665 in his car.
And my friend is a 8 degree black belt master complainer, with a master degree in whining.
He also have the V1 camera from back in 2013, it still work just fine and the focus never moved again, so sit in his drawer as a slide in replacement if the V3 camera should ever fail.
Other times i send parts of old test cameras to users around the world that suddenly have a need for a part, but this for the most happen with other brands of cameras i have been sent, i have yet to send old street guardian parts out.
I don't just think SG charge a higher prize cuz they can, it is still a small company clawing its way up the ranks, so they cant afford to just screw over people on the price.
But i must admit i can not tell for sure why they cost more, only the lens i can see are different, and on the inside some things might also be little upgrades, but i have no way to be sure other than taking 2 cameras and power supplies apart and compare them on a component base.
And the internet sites that do this with some things i have never seen do it with dashcams, but on phones they do it often, calculating that the new fruit phone or whatever you got for 1000 USD, well it just cost them 600 to make.