Still looking for speakers in the 10-20,000 range

I have the KEF Reference 5s and love them. They do everything that you like about the 3s, but just more of it.

They are also quite flexible with the type of amp you use with them. Do you want a front row seat in an intimate club? I ran them with a single MC275 and they sounded very warm and smooth and the music just enveloped you. Female vocals and acoustic music would just put you in a trance.

I recently switched to EC Nemo mono blocks and they are now just so dynamic and the bass is fast, tight and very controlled. Where the tube sound stage was deeper, the Nemos just exploded the sound stage all around with amazing detail and clarity.

As you know from the 3s, the fit and finish on them is wonderful and, though they are large, they are conservative enough to not stand out too much in a room making them very WAF-friendly.

I also have a pair of PMC fact.8s in my bedroom system.  At the lower end of your budget, they are also wonderful speakers if you are looking for a smaller footprint, yet keep that British sound you enjoy in the Reference 3s.

They are also well-made with furniture quality finishes.  The bass is better with the KEFs, but the fact.8s are really articulate and a joy to listen to.  I highly recommend an audition if you have a chance.

Hey fast, the Reference 5s do require a bit of break-in to sound their best. I don't really remember but it took a bit of time, for sure. 

Mine are 10' apart and I'm using the short ports with my speakers 18" from the back wall and 5' from the side walls.  They are toed-in slightly so the Uni-Q drivers are pointing over each shoulder in my listening position. 

I'm really surprised that they sound "digital" using an all tube system.  How many hours do you have on them and how hard are you running them? 

I'd let them break in more and, if you still have get the harsh treble, you might want to give your dealer a call to get some suggestions.