Since mine has it: 1. I'm 5'10" but when friends ride with me in the 6'2+ range they appreciate me opening it. Adds 1-1 1/2" or so to headroom. Don't forget to lower the seat too. I'm not sure how much headroom is lost without it but any lower would be bad. 2. Very sunny & hot days no problem in D.C. area I think because the glass is extremely dark tinted. 3. In my opinion it adds to the "UGLY" (read beautiful) look when its up. 4. I find it quietly ventilates the car far better than opening the side windows on moderate days. Go ahead and get it!! Bill 00 MCoupe Evergreen, Ostrich Leather 01 M5 Carbon Black, Carmel