Steve,
First, RWA no longer does SB mods -- and hasn't for a while now.
The older SB2 (I have one) has more room for larger output caps and the Bolder mods take advantage of this. As the room is limited in the SB3, generally, non-polar blackgate NXs are used, bypassed with a higher quality cap.
I only "believe" what I hear, what I read, after passing through my own BS filter, only either interests me enough to try it, or not, and if I try it and I don't hear it... back it goes.
The Bolder mods are the real deal, and if I weren't certain of that I wouldn't be sending another unit (SB3) and the top-of-the-line power supply back for mods/upgrades.
I'm an EE by education, and much of what I hear in my own system goes well beyond what I learned, and I have absolutely no explanation for it, and no matter how sophisticated the test environment, equipment, etc. are, I'm quite sure that at this point in our collective understanding of scientific principles, there is nobody who has the whole picture. Parts of it maybe, but the unified theory still eludes the human brain at it's current level of development.
-- Jim