True. Some of the caps they are using now are a huge improvement over what was available 20 years or so ago. Worthwhile.
I honestly don’t know of a preamp that is inherently better than the SF 3. I know of a lot using more modern or more expensive parts, but not better sounding or better designed.
I would not let a SF 3 go out of my hands. However, I might loan it to Chris to modernize the caps. :) In preamps caps have a very large contribution to the sound, and paying for an upgrade is relatively cheap compared to buying a new preamp with the same caps. You can really go up a few notches with the right cap upgrade.
I would however encourage you to listen to other british speakers like Monitor Audio and see if you feel the B&W's are still the best match.
Best,
Erik