Zu def 4 are they the best speaker made?

Oh. And I hope that I have more than a “handful” of years to live. 

Of course, I didn't meant to imply otherwise.  But, let's be honest, the industry is catering to older people who already have the money to spend on very expensive systems.  They are doing nothing to foster relationships and bring new, young people into the lifestyle.  I have walked into every stereo shop in my area and been treated like a second rate citizen because I'm young, and I don't dress to impress the salesmen.  The industry is missing out on a huge opportunity with the revival of vinyl in younger circles.  HiFi shops and exhibitors should be falling over themselves to talk to young people that visit them, not shun them for not having $100K to spend on their first set up.     

You hit the nail on the head when you said that Sean and his colleagues are, "invariably customer friendly."  They will talk shop with anyone and that is why it is so maddening to see how they are treated at times (not all the time).  They are the nicest, most approachable people in the industry.  I am very appreciative of companies and reviewers who put information on Youtube.  I used to walk up to them at shows and thank them for their work and information.  Not a single time did they look me in the eye and engage me in conversation or give me more than a one word reply.  Trying to engage the AV showrooms crew was the worst experience I've had since entering the hobby.

Back to the OP's original post.  I have never had the pleasure of hearing the Defs, but I have a good friend (that is twice my age) who has the new Druid Mk VIs and they are the best speakers I have ever heard.  They were good at RMAF, but in his home, they are mind blowing.  They are a completely different speaker than the Druid Vs and there is very good justification for the big jump in price. 

One point that was brought up earlier in the thread is that people don't like how Zu's product sounds with the amps they are paired with at shows.  I can tell you, that when you pair their speakers with the proper gear, you will be greatly rewarded.

My wife and I researched and listened to every option in our price range and not a single thing came close to the realism, sound stage, clarity, or emotion that our speakers produced.  Ignore the haters, most of them are shops or salesmen who don't like when a company sells direct and produces a significantly better product for a fraction of the price.  

Have you ever visited DejaVu Audio in the Washington DC area? Most of the staff are young and approachable. It is my favorite audio store. 

Sean delivered and set up my Def 4s personally. I have not moved them from where he positioned them. And if you call ZuAudio, a real person answers the phone, is helpful, etc.

I have not, but I'm headed to DC in a month or so, I'll definitely check them out.  

Sean, Gerrit, Harvey, Ian and the rest of the crew are all awesome people.  They are incredibly knowledgeable and know how to help.  

I’ve had my Def 4s about 5 years now and feel I can make some valid observations. They are very dependent on the amps and electronics upstream. Their transparency is revealed with certainty with the slightest variable introduced. Yes the right amps, preamp, front end, tubes selected all become a factor, I believe more so than many speakers due to the fact that the full range drivers are wired directly to the amps.
Their immediacy is startling and somewhat unusual, but their variation on different source material tells me they don’t color as much as reveal what the source provides.
Another pair of other factors are significant. The down firing subs are sensitive to room placement as distance from the walls and reflection play into the equation. The other factor is their sensitivity. While this makes them ultra dynamic in both a macro and micro sense it also causes them to be very sensitive to noise in the electricity. When this is addressed effectively depth and presence increase, giving a very in the room, at the hall presentation.  With the elimination of crossovers very little is masked and realism is there in spades.
I doubt the audio shows allow this level of setup and this is largely responsible for the widely variable opinions regarding them. Frankly, with dirty power they can sound pretty shouty. 
Spirit’s opinion as stated "in his room" carries more info than might be evident on the surface. When one has a speaker like the Def 4 the potential begs the effort to address what might bring it to fruition. Some things are just worth working for.