Next best exponential DAC quality level?

I currently have access to four DACs in my home -- I own 3 and have the fourth one as a loaner courtesy of a wonderful friend.

DAC 1 -- Bluesound Node 2i (owned for more about 2 years)

DAC 2 -- Audio Mirror Tubadour III (non-SE version; owned for 1.5 years)

DAC 3 -- Luxman DA-06 (owned for 1.5 years)

DAC 4 -- T+A DAC 200 (loaner)

Please don’t listen to anyone who says there’s no difference in sound quality. There is absolutely a vast difference between DACs at different price points. The higher end DACs give you a wider soundstage, more air around instruments, better tone and timber, and most importantly a significantly darker background (compared to lower priced DACs) that results in a more detailed resolution. The better DACs also provide a sense of ease where the music just flows like liquid.

The problem is that most of the ’it all sounds the same’ crowd is too busy reading graphs and charts, and never bother to actually listen to some of the better DACs in the market. I can tell you that the differences I mentioned are not subtle at all. You will immediately hear the differences provided the rest of your gear is up to the task.

So between the DACs you have what was your favorite in priority?

I didn't say there's no difference in sound quality. I said once a DAC has reached a certain point they will basically sound the same. For instance a MHTD Pagoda injects enough distortion to have a sound signature. The problem with the DACs all sound different crowd is they have never controlled for bias or level matched properly. I have listened to a lot of DACs , some fairly cheap,  some expensive and one thing I've learned over the years is price does not necessarily equal performance. 

@arafiq  I also have the Hint 6 and am using it's DAC- the ESS Sabre32. I am still fairly new to higher end audio and I am going to dedicate myself to digital. I am streaming Qobuz hardwired through a Bluesound Node 2i. My speakers are Dali Opticon 8. I prefer the Parasounds DAC much more than the BS Node DAC by a wide margin.

No matter how much I read I have been unable to decipher what makes one DAC better than another. I understand the concept of things that cost more generally tend to do so because they are better but in the case of DACs what are the metrics? What am I looking for spec wise? Specs matter more to me than name. Also out of the DACs you named and are using which do you prefer?