I don't own a Varia, but quite a few of my friends do. They also swear by it. I'm the only one who runs cameras on rides, both front and rear. I think if I cared about looking like a dork I'd ditch my helmet mirror and get a radar. I'm okay with looking dorky so I'll stick with my mirror.
I've sat behind their wheels with it flashing. I don't find it all that bright, or maybe I'm just used to it.
The cameras, while they won't prevent any collisions, do give me some peace of mind, especially when riding solo or on my commutes, in case there is an incident. I don't usually turn them on when riding with a group. And if I do, it's sporadic.
I view the Varia the same way I view my cameras--that if it gives you some sense of security, then why not, even if it is a false one.☺️