I am 5' 8" with a mustang seat and the 11".

It works great with it on the lowest setting (right our of the box)
I need to experiment with is more but it works so good I have not touched it after the install.

If anything it may work better if it was even lower / but the 11" is the smallest available.

I have the extra dark and it looks and performs great. As many have said it is one of the best things I have bought for the bike. I look completely over the shield. It comes to my chin and if I were tall I would get one that was even lower. It shields the wind so well that it could be a few inches below the chin and be even better. It would almost be like having no at all.

I thing my F4 customs with the vent is almost just as good but it does not look as good. I may try it in the winter when I need more air protection in the cold weather. Time will tell / Maybe if I just raise up the Madstad I will be ok / but with it being extra dark I do not want to look through it at all.
Steve