B&W vs. Sonus Faber

Not sure buying used spkrs is a good idea.  No idea if they were abused and you’ll never have full confidence about what you have.  
Used cars ok, but speakers a lot tougher.

I’d much rather buy old speakers instead of used cars. As long as the speakers are less than 5-7 years old, there are fewer things that can go wrong. I’ve bought almost 7 pairs of speakers in the last 15 years, all used, zero issues. Knock on wood!

I agree. I don't see many people spending say 6 or 8 thousand dollars, if not more on high end speakers abusing them. Or any piece of high end audio equipment for that matter. I think most tend toward being obsessive about their gear. I know I am. 

 I would be far worried about  buying a used car.

B&W on the other hand will grab your attention immediately. Once you take them home, YMMV.

B&W D3 are a very revealing speaker and can be picky with components.  The amp/preamp can make or break this speaker as I have heard D3 sound like crap or sound boring but also sound totally amazing.

The Sonus Faber are going to be more forgiving on bad or flawed components, so they will likely sound more "pleasing" in a higher number of systems.  But they are not going to be as transparent or accurate in the high frequencies as the B&W diamond tweeters.

I recently purchased the SF NOVA 5 after comparing them with several speakers including the BW 803 d3.  They were both excellent sounding, however the Nova 5 sound more natural to me with smooth high and mids,  and a well-definded base.   The B&W has more of a British like KEF.   I mostly listen to Jazz, smooth rock, and classical if that is any help.