What makes you think there’s any performance disadvantages?
You have vastly more tread on the road in the flats.
Rear braking is accordingly insanely better in an emergency.
Wet road performance is better.
You have about 4-6x the contact patch on the road in a corner vs a MC tire.
I’ve gone through advanced riding training courses and done a lot of pylon parking lot work with a DS tire on (I posted a video here last fall of doing exactly that for that matter, I’ll see if I can dig it up) and the rear tire doesn’t affect anything high-speed or low speed manoeuvring.
I ride hard on my tank, I’m often on the floorboards (and touch the pipes occasionally as well) and it performs every bit as good as any motorcycle tire I’ve ever used. I’ve ridden somewhere close to 100,000km darkside now and won’t go back as not only are the tires half the cost but I am not paying labour 2-3x a season to swap the rear given the miles I ride, or sweating my balls off in the garage doing it myself.
And on anything short of a sport bike (which isn’t the darkside target audience) you’re not “riding on the sidewall” in corners which is the big argument people who have never read much about the whole thing rush to.
With the appropriately sized tire I would put money on the fact that in a blind test there are a lot of very experienced riders here that couldn’t tell the difference in a ride test. Heck, I sat next to a buddy with his gold wing yesterday and not only is his rear tire basically the exact same size as my 195/55, with his highway mile wear profile the tire looked almost identical to my CT from 20 feet away.
As long as the tire is DOT rated you’re fine.
The insurance thing is another common potential problem that is often mentioned but it’s not the big thing that people perceive it to be – insurance companies don’t get to arbitrarily walk away from claims simply because of things they don’t like, if they did then there would be something they could latch onto with every single possible claim ever to weasel out, which simply isn’t reality. Heck, you can crash your car in a DUI wreck and your insurance will still cover you. They will probably cancel your policy after the fact, or at best refuse to renew you when you come up for such, but you will still be covered for the actual accident even though it is a wildly inexcusable and entirely stupid thing to have done to begin with. But ultimately you’ll still be covered
Anyhow, this “notice” from Virginia has been a topic of discussion in the dark side community for sure. First, given the lack of professionalism and poor grammar there is some question about its legitimacy to begin with, and then there are all sorts of arguments about how enforcible it even is to begin with. How about people with trikes for example, they all run CT’s. Things like the Boss Hoss etc come factory with a CT. Etc etc.
Anyhow, much like many things in the Motorcycle community, everybody is welcome to do as they see fit and please. I am extremely happy with my dark side choice, it saves me time and money, has real world performance and safety benefits, and it certainly doesn’t slow me down anywhere. Someone’s welcome to come take a ride with me and see for themselves, I have some nice traffic circles we can blast through at speed and you can watch me flip my bike through it every bit the same as if I had a MT on it.
I was quoting the rescinded regs page that 
