In reply to drolex:
I've also used them occasionally in Scotland, having bought them to use in Pyrenees. Certainly useful on occasion - I think maybe conditions tend to change more quickly (as you walk along) in the UK, so you don't always get long bursts of deep soft snow like you might in the Pyrenees - so maybe more taking on and off.
But always very satisfying when you walk casually past someone struggling to break trail in knee deep snow