I tried a vario, but found it presented more surface area to the oncoming wind, so was worse than standard at speed, but better at slower speeds.
Went for a puig double bubble, and it was much better at speed. It lifted the weight higher up, so I was getting it in the shoulders, as I always will (I'm over 6"3 - but currently just under 19st) so the extra girth definitely has an effect too. A big one!. The major advantage of the double b, is that you can get in behind it, and it's then superb, if you're not too wide further down.
A big influencing factor I found, when I was not so fat (around 16st) and hence not as wide, was my helmet. I went from AGV, to Caberg then splashed out on an Arai RX7, and that was the dogs danglies. I had substantial helmet "lift" with the other two, but I got the Arai deliberately very snug fitting, and it didn't move upwards half an inch at 155+. I even turned my head sideways and rotated it to see if there would be a difference but it was solid as a rock. I could actually sit up, and forget about the lid completely, and not be mullered by buffeting either. Down behind the tank was brilliant. Earplugs are essential for high speed work though'
I'd never heard of removing the mirrors before. I have a chromed cruiser type of mirror - screws into the right hand side, and has little wind resistance, so I might give that a shot later. Looks great as well. Different horses for courses, but with the standard screen I was being lifted back on the bike, and wind hitting me around diaghpram level. Total pants. But a rider below 6" should have much better success with it, and with the double, provided they are normal frame size, shouldn't have too many issues at all.