ok so my response got me thinking, and I looked up better bottles FAQ and found:
" . . make a PET conical fermenter? – Large-scale, conical fermenters, used in conjunction with filters, are definitely effective; however, on a small scale, things do not work out so well. We tested a prototype of a transparent, PET conical in our development lab and we saw what cannot be seen in opaque conicals. Fine particles settle on the sloping walls of the conical section and remain "stuck" there, until the liquid level reaches them during racking. Then, they contaminate the clarified wine or beer. Racking was not nearly as clean as it is with our standard carboys and racking adapters. There is a reason for drawing clarified wine or beer from above the sediment during small-scale racking. Nevertheless, a conical made of our PET would have many advantages compared to conicals made from polyethylene, polypropylene, or polyvinyl chloride. The PET conical would be essentially impermeable to oxygen, would not stain, would not add or transfer flavors, would be transparent, and would be a great deal easier to clean. Unfortunately, a PET conical would also cost more, making it quite impractical in view of the fact that Better-Bottle racking-carboys perform better in any case."
uhh, so what if a thin layer of trub stayed behind? the idea is to get most of the trub out for yeast harvesting and clarity. What are they waiting for? Maybe if their racking arm was a little longer it would not pick up the side trub.