The one at the end of the M62 probably not so much now, as so many people have been stung by it. Never see anyone get caught by it these days.
I remember when it was first brought in. Literally every time I went past there'd be someone flying past it, sometimes more. We did rough calculations at the time and worked out it was probably earning about 15-20k an hour.
There was another one around the same time on the park way in Manchester, but a mobile one. Same there, everyone flying past it.
One of the worst I've seen is a mobile camera at the bottom of that big hill on the a55 in Wales. Proper snide that.