Morgan,
My Bybee Purifier was the mini (retail is $1500 vs. ~$5000) though Mike had done some extra stuff to it to bring it up a notch. It was a nice piece but the presentation of the Buss was more natural. Its been a while and I'm going from memory here, but there was a smoothing quality to the Bybee which complimented my previous Zu based rig nicely, but left this system (Von Schweikert/Melody/Lampizator) sounding a bit overly smooth and sleepy. I've also come to the conclusion that my Lampizator would rather be plugged into the wall then a Bybee purifier.
It was actually a part of what almost led me to the hasty decision of selling off my VR-33s too soon.
The Bybee was a good product and will satisfy in the right system, but I have a more visceral and alive sound with the Buss that wasn't compromised in refinement or noise floor.
I had listened to both the Uberbuss and the Bybee Power Purifier in my prior system and my preference was inconclusive on a single audition, but I was getting ready to buy the uber suspecting it the more versatile product, when I was given an offer I couldn't refuse on the bybee--that guided my purchase decision. I'm coming full circle and am quite psyched to hear the Uberbuss. it will have 2 of the Furutech receptacles and 1 Porter Port.