Well i put 16 hrs on my brand new Certified Pile Brush on the weekend doing salt laden entrance mats and cgd entry ways into commercial buildings and i must say i am thrilled with its speed and performance. I have 3 almost a year old 18" All Metal Royal Vacuum cleaners to compare with and must say that when it comes to the real tough stuff the Certified Pile Brush make my Royals look like a childs toy in comparison. The Pile Brush has the same vacuum motor as the All Metal Royal but can pick up stones and other very large debri with out damaging the motor or plugging anything up. The large stiff 1/2 HP driven Brush and overall design is the big difference.
Given that speed is money but at the same time you cannot sacrifice quality for speed, I will be using the Pile Brush in only the more challenging situations such as entry traffic lanes in commercial, trashed empties and it will pay for its self many times over in speed and quality of work.
I see this as one of them machines that may not be used every day but when needed it will be worth its weight in gold.