I wrote this review on another web site, but I though it worth repeating here.
I have both the Cadillac windscreen and the WindRestrictor. They are both excellent products.
Value - The WindRestrictor is the better value. I got a model without etching. I worried the etching might interfere when looking backwards. (I was tempted to get the Cadi logo as I think it really looks sharp.)
Wind protection - They both stop most of the wind. With the windows down, the Cadi windscreen stops more of the back draft that blows hair forward. With windows up they both stop most of the wind, but the windscreen still stops more wind.
Looks - I think the WindRestrictor is much better looking. It certainly looks better than any of its cheaper competitors that I have seen in person or in pictures. It is solid and thick, cut and polished, sits in a leather frame, and looks very professional. (I am surprised some people would buy an $80,000 car and worry about saving $100 by buying a flimsy windshield. Don't mean to judge, just find it odd.) The Cadi windscreen looks OK but it does not add anything to the car, at least not to me.
Packaging - The WindRestrictor has better packaging and extra touches including cleaner, cleaning towel, and gloves for installation to avoid hand prints, even though they would easily clean off.
Speed of install - The windscreen goes on and off in less than 5 minutes without tools. The WindRestrictor requires an wrench and takes about 5-10 minutes, plus you have to be careful not to scratch it. The windscreen has a storage container. I saved the shipping box to store the WindRestrictor.
Interference with vision - The windscreen interferes with my vision when looking backwards, especially at night. The WindRestrictor reflects light when it is darker behind the car than in front, somewhat annoying. I think they used a special plastic to help keep the reflection to a minimum. Overall, the WindRestrictor causes less interference than the windscreen.
Bottom line - You cannot go wrong with either. My wife likes the windscreen slightly better because it stops the back draft better; therefore, I like the windscreen better since I bought it for her.