Best speakers in the 3000 -5000 range

OP, can you explain what it is you are looking for your speakers to do differently? What kind of sonic change are you looking for? What would an "upgrade" mean to you? Absent that, we can only recommend "good" speakers in your price range, but we are looking for different things, for example I am much more concerned with midrange accuracy in timbre, and would sacrifice ultimate bass for that, which is why I own Merlins, they provide the kind of sound that appeals to me. Have you heard any speakers that you liked better than what you have, and if so, in what way? Maggies and Harbeth are very fine speakers, but they may not be doing what you are looking for, where a Vandersteen 3A might very well do. IOW, more info please.

Bob, you are making too much sense, stop it.

Condescending? No - I don't takes this stuff that seriously. The point is that all
the advice being given absent knowing your preferences is close to meaningless
- hope that helps. What would help us is for you to tell us what it is about the
804 that you are looking to change or improve upon - what are they doing or
not doing that is making you look for another speaker. That will get you better
advice specific to your sonic taste. That being said, a similar sized and class
speaker in your price range that works well with SS amps would be the Thiel
2.4s

I have never heard the Focals. When you say faithful reproduction, I assume you are talking about timbre (as oppose to sound staging and imaging) - which I think B&W does pretty darn well. Some of the most timbrally accurate speakers I have heard are the Merlin VSMs which may be in your price range used. They are not bass killers, there is some small sacrifice there, but very accurate and realistic in the mid-range. I would say the Thiel is in that camp too, very accurate timbre and revealing, resolved speakers. You are at a price point where there really are a lot of good choices. What if any dealers do you have in your area where you might be able to audition? Thiel has relatively wide distribution, Merlin, not so much, and while they can play with most any amp, they really do need tubes to show their stuff, whereas Thiel almost requires SS to be their best.