My brother owns the Audible Illusions. +1 regarding customer service. He sent his in for a service and they talked him into buying a replacement. Then they sold the one he'd sent in to somebody else and he had to wait a looooooong time before they sent him a new build replacement.
I own a supratek Cortese. In my opinion the Audible Illusions is not in the same league as the Supratek. It sounds like a solid state preamp. That's just my opinion. For those who enjoy the AI, please don't allow my comments to diminish your enjoyment of your preamp. They are universally very highly regarded and have been a recommended buy for decades. So they must be doing something right. It just seems to me that my Supratek digs more tone out the music. Instruments sound richer and fatter. More meat on the bone, so to speak. YMMV.