The Stage 1 WAS built off of a dmax turbo. Now it only uses the LLY Dmax compressor wheel because Adrian doesn't have to buy the whole turbo anymore and just has a stock compressor housing machined to accept the dmax compressor wheel. Kind of like what Danville does with their dmax turbos.
The Hybrid also has a machined compressor housing that uses a billet GT4088 compressor wheel. As Chris mentioned, it is really only about a 20-30hp difference between the two turbos. Also the billet wheel on the Hybrid is taller than the Stage 1 wheel so the blades are bigger and should flow more air up top than the Stage 1. Hope this helps.
EDIT: Yes Adrian is the one who builds them.