Elizabeth - Great answer, but why do you feel power suplies are so unimportant? Only Half :-)
You're quite right how it sounds in your system is the most important question. But how do you know how it sounds. Retailers in Australia carry limited stock and most are unwilling to lend out,except maybe for the stupidly named Dave and Hugo dacs, which are out of my league anyway. So I have to rely on the views of others. Those that have bought expensive dacs are, I believe, pyschologically inclined to believe their purchase was worthwhile and those that have bought cheap dacs like to think they have a bargain unless it is obviously crap. So that leaves reviewers, both the golden ear type and those inclined to believe measurements. Reviewers of both types have gone to print to say that cheaper dacs such as the Topping D50, SMSL SU8 and JDS EL DAC are excellent and that they hear or measure little difference between these and dacs costing over $1000.00. Then there are the unknown Chinese sellers with dacs sporting top of the line components at bargain prices but as has been pointed out implementation and design are key and who knows what the Chinese dacs are like. I must admit that my one experience buying from China or Hong Kong, as it was then, was positive. I bought an Audio Experience Symphonies V2R preamp from Y S Audio for around $300 and spent another $200 on mods, mainly Blackgate caps and replacing the miniwatt tubes with NOS RCA 12ax7 tubes. The guy that did the mods, a genius who custom makes amps costing megabucks, concluded that the amp was very well designed and after the mods was as good as any US or UK pre the he had heard for less than $4000. So where does this leave one? Confused I think. I'm tempted to take a chance on something like the Topping or even one from a lesser known Chinese amp builder like Weiliang or Ustars as funds are limited but then again there is the question whether I would hear a positive improvement over my 10 year old Denon Exemplar CD player. Maybe I should do nothing and be content with what I've got but that is not the way of Audio Geeks.
To my ears, I would describe the Burr Brown in my Denon as well as my Cayin as 'Chocolate'; the ESS Sabre in my Oppo like 'Vanilla'. They sound different; but is one superior to the other, I would say no. I haven't tasted the AK so cannot comment, but I suspect it would probably taste like 'Strawberry'. Now that is all I need to have a Neapolitan sound system. :)