I wouldn't use it on m50, but on the n7/m9 I use it all the time, as I said I'm going against the traffic so not that busy, not many lane hoppers!Regular cruise is a great job too on lightly loaded roads, I use mine all the time commuting. but in heavy motorway traffic here people would constantly cut in front of you surely? They do it all the time if you try to obey the 2 second rule in heavy motorway traffic, can't see how they wouldnt do it to adaptive cruisers too.
I assume it must be illegal in italy, you'd fit four italian cars into the gap