The only thing we can really do is use borrow or return policies to listen in our system. I am still looking Gustard, Topping, SMSL, RME, JDS, Schiit, and hope to borrow a Qutest ( big bucks) to see if they really are smoother. I have a very specific sensitivity to vocal sibilance. Others are looking for detail, others impact.
DACs, though they do sound different to me, are close to the last component to look at. An Apple dongle is better than many amps and I venture to say, all speakers.
Aries II, renamed ENO, also jumped in price to $1200. Too many positive reviews I guess. Over budget, but it may be worth it. I hope to try one.
DACs have gotten much better recently, so a 2 year old winner may be mid-pack now. I still have not found one under $500 that can beat my $99 JDS. I'll take it over a Cambridge and about any esoteric brand any day. I have not heard a built in ( integrated amp) that is significantly better. DAC sound is 99% the input and reconstruction stages. The actual DACs are so good as they don't make a big difference. I doubt audible through speakers. Maybe really good cans.
Gleaning many many subjective reviews and some objective measures, the Geselli is a very nice DAC. Choice of DACs, choice of op-amps. But it's USB is terrible. Of course, it will measure well on a $20K measurement box as it will have a clean USB output. Not so on a PC. The new SMSL DO300 seems to be pretty widely accepted sonically and it also measures well. I am curious how good the Hugo is compared to a Qutest as it falls under 1K. Gustard X16 has my eye.