Hi Michael,
Yes, that link sums it up pretty nicely. I've heard both the Backert Labs preamps and agree with the heart of the PFO review. Didn't get to roll any tubes, and IME that implies an even higher ceiling. I like the clever magnetic "pop-top" in the luxury model.
FWIW, Backert is no rookie. He has been doing mods to Conrad Johnson and many other top brands for decades under his other business RHB http://www.rhbsound.com/. Since Bob is a member of our local Philly area audio club (www.paagonline.org), I can say from personal experience that you won't find a more credible, humble and talented guy in the business. Many people I know have raved for years about Bob's ability to improve the sonics of their high end preamps & amps.
I hope to check out their room at Capitol Audio Fest w/Martin Logan. Cheers,
Spencer