Does what it says, will definitely have it on mine. I like not getting my mirrors knocked in the parking lot.
The only minor issue is that it's not specific to the mirrors but rather activates the CA closing procedure so the windows move a little depending on how fast you are with the button. I tried increasing the time before the windows start closing (KMFRT_SCHL_VORNE) but it had almost no effect except after the doors locked they clicked again almost as if to be unlocking. Did you have the same experience?