It all depends on how tall you are and more importantly your riding position. The double bubble does throw the air up higher but if the standard screen gets you in the chest now a double bubble will get you in the head causing more noise and turbulence. Add that to the fact that the aftermarket screens are all slightly different and then you have the higher Givi and the flip type and you can spend a fortune trying to find the right screen for you. If its getting you in the head now a double bubble may throw it over.
Its the wrong time of the year now but your best bet is to meet other members and try their bikes with different screens.
I've had a Powerbronze and an MRA double bubble but keep coming back to the standard screen which I've found is better at higher speeds and less noisy round the head, the wind pressure on the chest helps with comfort as well taking the load off your arms/wrists. I don't think you can really compare heights either to try and find the right one, same height people can have longer bodies/shorter legs and vice versa.
95% of all Harley Davidsons ever made are still on the road... the other 5% made it home.