Thanks for the great reviews and comments. I was really suffering from a huge amount of wind noise and buffeting on the R3 GT so was thinking about an alternative screen to push the air flow up and over my helmet. I'm 6'1" and with the factory fitted screen the air seemed to hit the underside of my full-face helmet, which amplified the wind noise to deafening levels (I changed helmets, ear plugs, etc., to no avail).
It was so bad, I removed the screen yesterday evening and, "Wow!", what an improvement! I found it vastly improved and smoothed the airflow around the helmet, so it's much, much quieter. I've tested to three figures and it seems great at speed, whereas the standard windscreen would get very rough at anything above 60. The airflow hits more in the torso, thus keeping one cooler on a hot day (especially necessary with that 2.5 litre thermo-radiator we call an engine strapped between one's legs). I guess the other benefit is that as I have to hold on more, it will help to develop my core strength (I've been working on my one-pack for years) and allow me to finally abandon that long lost New Year's resolution of one day joining a gym. Indeed, one could almost see that as a cost saving and put the time and those extortionate would-be gym membership costs into clocking up a few more miles on the Rocket.
Perhaps if ever I feel the need in the future, I'll consider the Madstad or Powerbronze, but for now, I'll keep enjoying the airflow.