well, i just placed and order from latemodelresto.com for the Professional products 75mm tb AND plenum for 200 bux. not bad of a deal, on backorder though, so i cant tell you how good or bad it is till i get them in a about a week, and i havent read of any one actually hating the product, so the price plus that = me buying them.
cant go wrong i guess unless its made of plastic or foil.