That would be interesting. never seen that myself. we use and highly recommend the Groundskeeper 11 rake from Wesspur. power cleanup is a good thought, as long as you have hard ground. i'd hate to try and save time only to have to re-seed a lawn. i'll look forward to checking out what comes up here. . .
The bmg rake works well with dry ground. I borrowed one for a 12 large dead ash removal job. Saved hours of clean up. It was the right tool for that job
I've been thinking of making my own BMG but would like the rake as well. The materials add up pretty quick to make the grapple but see there can still be a good saving if I can find the free time to make it. I have yet to find the material to make the steel rake but someone told me to look at street sweepers.
I own the bmg broom. It is incredible. Had it 5 years and it needs the bolts tightened. On big removals it saves hours. One job we estimated it saved 10 man hours raking. The best part is the thing catches the worst nastiest junk that is the hardest to get with a rake or pick up by hand. When it is done sweeping you can blow whats left typically.