Have you heard LTA Aero, Lab12 Reference, Denafrips Pontus 15th?

If you are looking in the $4K range, suggest checking out the Holo Audio May DAC.  Cost $4,200+ new depending on the build you choose.  End game for some.  

I'll be following this thread as I'm interested in the holo audio may KTE as of now,  originally it was the LTA Aero. I purchased a pagoda balanced from LTA and they do have excellent service I agree.
 

My Pagoda's usb socket shorted out and I had a local guy repair it, he says it's a design problem, idk. I just know it works again.  LTA no longer sells mhtd labs DAC's  but still responded with diagrams of the pcb and known chip to check for damage. Very helpful 

They had the LTA Aero's set up for headphone listening at Capital Audio Fest. Also had it integrated into a system with massive planar speakers. Sound was very smooth. I was also there to check out the Geshelli Dayzee - reviews of this put it up there to compete with the Aero and it has more connectivity. They hat that integrated into a system, but the system was so much different than the system that the Aero was integrated with that it is not a good comparison. They did not have the Dayzee hooked up for headphone listening either...I may re-visit, currently using my bluesound vault as my streamer DAC, it will do for now. I learned at the show that the biggest difference I can make in my system is to adjust the room...and get a turntable.