I got the option when I purchased my Civic. I had one in two previous cars, and wanted to keep the trend going. Plus, my wife always used to flip the darn thing the wrong way!

Then I'd be flipping it later when I drove it and I'd be looking at the ceiling - or the rear seat...anything besides directly behind the car.
I have seen several threads from people that have bought this option, and even installed it themselves. I just had them do it when I got the car...along with fog lamps and the rear chrome tail pipe (which looks very sharp, IMHO).
Anyway, as far as the visor's operation...I haven't had any trouble with it. It is always dark enough for me. And the compass is useful sometimes...when you aren't using GPS or didn't buy it.
I would say that it is well worth it. Then you don't have to always drive with these on...

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By the way, Hey Otto, That is a pretty sweet visor too!!!