Bob,
We both have them. My wife's (5'7") is a 2+, 2+ Flip, Mine (6')is a 4+ X 2+ Flip. We both absolutely love them. We feel it is the best windshield we have ever had. Not sure how the passenger would fare, but, since your wife rides too, it should not be a problem.
If I were to do it again, I might go 4+ on the sides. Still a little wind coming through. However, I live in New Mexico and there is ALWAYS wind here. Plus the wind never comes from the front or the rear....always seems to be from the side.
I initally thought 4+ would be too high. But, now that I am riding in some 30 degree weather, I am happy with it.
Being a worry wart, I sometimes wonder if the brackets will bend or the motor will quit. At 85-90 into a wind of 30 or 40, it takes a beating.
Also, given the blowing dust we have (read sand blast), the windshield seems to be holding up pretty well.