Seems obvious to me from his post that these are motors that did not make it into full production for one reason or another, and seem to have no future with CC. Hence no warrenty. CC obviously learned how to make them better and moved on with the motors currently in regular stock.
Kind of like buying a Delorian. No warrenty and no replacement parts, which means if you bought one you are stuck with it no matter what happens to it. Once it breaks it becomes a paperweight. For the price what can anyone expect? At those prices it is a throw away. Put it in, use it, and once it fries you toss it in the trash. Sounds simple to me.
Some of them are discontinued. The 15xx motors are just WAY overstocked...
Patrick del Castillo
President, Principle Engineer
Castle Creations