I had Night Vision on my F10 550. I'm not quite sure why I added it, other than me never being able to order a car without checking all of the option boxes.
As a few have stated it was a novelty. I rarely ever used it when I was driving. I usually only switched it on when I was showing the car off to family and friends. When I ordered the M5 I purposely left this unchecked even though it leaves me with a blank button.
In use, you have to look at the iDrive screen to see the outputted image. It won't appear in the HUD. This is distracting. While it was pretty decent at locating pedestrians it wasn't completely accurate and would sometimes alert when I was completely in the clear.
Aesthetically, I don't think it detracts too much from the front of the car. I had kidney grilles custom painted, and if you don't want to go that route, iND also sells a set that are basically the same thing.