The 8B is a little more rounded, and softer on drum leading edges. I would say the Marantz reminds me of a French pointalism painting, with lots of delightful tones and pistaches of coloring, while the Fairchilds are a Dali painting, a little mind bending in what they can produce, hypnotizing you to follow all the quirks and rabbit holes you thought a tube amp would never take you, especially in the bass nethers you had reserved only for solid state amp.
I could use all the key words the reviewers parlez with, but to me a great amp is more about how it sets your frame of mind and physical state. A great wine, a fantastic meal, a rich beer, and a fun jazz album all take you someplace in multiple ways...for me, so does a great amp. These, along with the Mac MC30, are some very, very fine vintage glass.