I know its standard on most BMWs in the NA now. In HK they still charge USD 3500 for it as an option, so I didn't order it.
My last car, 335i had it. It also an option (about 1000) and all the cars on the lot had it so I got it since I didn't want to wait 3 months to get a car without it.
When I had it I probably remembered to use it like once a month if at all. I never fully opened it, because didn't want dust in the car and always either had heating or AC on.
What is you take on the sun/moon roof?
2010 E90 LCI 325i (Hong Kong)
Sold E90 335i M Sport (Tokyo)
Sold E36 328i (NYC)