I've used the laser on my i8. It makes a huge difference. On my car the trigger is 43 mph. Unfortunately, I have not used it much on the highway as I'm rarely alone without traffic ahead or coming towards me. I did use it at 5 am. And 43 is a bit too fast for neighborhoods. It is a great option but usage will vary depending on where you drive. I still haven't recouped the amount charged for this option.
Don't know if it's different from the X5.