Well for what it's worth I am in the same position to make up my mind for a winter shield, I am trying to decide between the two taller ones from CB, however it's not just for me it's for the wife also. So I am trying to find info from that direction also.
Another thing is I don't know whether the sizing on there website is versus the 08-09 or 10-11, and some of the threads I searched are the same way, not sure when some talk about there shield what year the bike is they have.
I am 5'11" and I got the Euro. From my perspective it is a big improvement, not much bigger than the stock but a much better shape. I didn't get the Ultra because I did not want the screen any higher in the fully retracted position for when I am aggressively riding the twisties (I live in central Co so that is what I do most).
From my wife's perspective the change was massive. She could not believe how much better the Euro is over the stock shield.
When I was looking for the shield I called an on-line retailer because their site only said 08/09. They got back to me promptly and said it was good for the 10/11 models. The other thing I have seen several times in the forums is that the "new" windshield for the '10 was simply the existing "taller" option form the 08/09s.