I have had it on my BSM e90 for over a year. It does what it says it does. It seals the car and pretty much nothing sticks to it (within reason).
This has proven to be a double edged sword in some cases. Waxes, etc... that you would typically put on top of the clear coat to act as a sacrificial barrier against small problems also don't stick very well. You have to be careful because if you do end up getting marring/swirls etc.. they will be in the opticoat layer and you will need to polish them out. OTOH the blemishes will be in the opticoat and not the actual clear coat so thats probably a good thing as you can then polish them without taking down the clear.
I also think there are sealants/waxes that "pop" more on black cars, but by no means does opticoat look bad.
If you are going to get it, I'd have it done by a professional who can correct your paint as close to perfect as they can before they apply it because once its on there, its on there. They only way to get it off is by polishing it.
Last edited by asus389; 04-13-2013 at 04:17 PM.