Are mechanical poo-pickers a viable option?

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(Image credit: credits-unknown)

My yard owner has agreed to invest in some kind of field/manure cleaner. How efficient are they and can people of any age drive them on private land?

Opinion is divided regarding the efficiency of these machines. Common criticisms are that they are impractical — as the operator may need to keep getting off the tractor or quad bike towing the machine to operate the suction hose — and expensive because they consume a fair amount of fuel and cost between £2,000-£5,000 to buy.