Warby, I can tell you live across the pond from me - lots of lingo I need to learn.
As for the Harley - once you get to solid debris (stones, block) that's larger than about 6", you may start bouncing over some of it. But this is our 6th season using ours, and it still works like a charm. A couple things I learned - don't run your skid steer with a full tank of hydraulic fluid - that added pressure when the drum binds up can cause a hose to blow. With that, always keep an extra hose with you (we keep one strapped to the rake itself), in case one does blow.
It's a great machine.