Interesting product. A lot will depend on pricing, but at similar pricing and efficiency I think you'd have to give the nod to the SP20 due to many of the reasons other people have listed here (established product, ease of changing settings), but also due to the potential risks inherent in the chained design. Bitmain saves significantly on costs by eliminating the VRMs and should get a small efficiency boost from it as well, but so did AM and everyone saw how the Prismas turned out. This wouldn't be a product I'd be investing a lot of money into until the first batch is field tested for awhile.