Hands up I admit to being a Lampi user - it out performed my previous playback MPS-5 when I borrowed one to compare in my system. I have not any experience with the Kassandra or AN Dac 5 - they are outside my price range by a large margin. The Lampi is not cheap but does not have an outlandish price tag like the current "uber" DACs, the Kassandra ref I believe is 3 times the price of the GG and the audio note Dac 5, I think, is in that region also, dcs, msb go up even further.
If you are able to go for these options then naturally you would want to try them, I am sure they are excellent and presumably any prospective purchaser would want to try them in a familiar setting. Which leads me to the the point I wanted to make - whatever piece of equipment is being assessed within a given system, the auxiliary equipment will influence the final sound. Preamps, power amps, speakers will all impart their signature and become part of the final equation. A piece of gear may perform well in one system but not so well in another. For instance different computers and even OS can affect the sound produced, cables can make a difference, room acoustics ad nauseam.
When someone posts that so and so a dac/speaker etc is not for them, another listener could well espouse a dissimilar view of the same unit within their own setup. Hence the endless debate, individuals preferring this or that component over another. Needless to say, if we all liked the same type of sound, or our systems produced music that was indistinguishable from one to another, there would be no debate and all the boutique manufactures who have sprung up this century would go out of business.
btw I have shared some of Keds tube rolling experiments and consequently had my GG moded to take 242 valves to great effect (I am sure his Lampiness is born of enthusiasm - don't think Lukasz could afford his travel expenses anyway lol)
The result is organic and fluid sounding and compares very favourably to my analogue set up which is, if not ultra, at least high caliber.