Very interesting.. Did you have a preference between those 5 dacs? Or would you judge them to be roughly equal, but differing in their different signatures and compatibility with different headphones? Between the different amps and headphones I've heard (and even standalone dacs, but I've only heard 3), I always found that I preferred one over another in A/B comparisons.
Keces 131 mk 2 and DAC19 is the one I got the most enjoyment from. They are quite different as mentioned and thus synergize best with different headphones and/or music genres.