10-15 year old hi end DACs are still great.

My experience is that older DACs often have excellent power supplies and analog output stages. Those seem to be areas were designers skimp these days, especially with just using simple opamp output stages that measure great but don't sound all that amazing in a lot of cases.

On the other hand, older DACs will often be limited on their USB capabilities, if they even have one. Which can be overcome by using a good DDC to convert to AES or whatever you prefer.

I still have a Luxman DA-06 from over 10 years ago. Original price maybe $6k, now sells for much much less on the used market. I've heard it beat many new DACs, especially when it comes to midrange body, layering, and richness. Same goes for my ModWright Elyse DAC which replaced the Luxman. 

My experience is the contrary. Not long ago I offloaded an Electrocompaniet ECD-2 ($3000 and SOTA measurements in 2013) because the DAC in my $320 WiiM Ultra sounds better. Concerning DACs, price has very little, or often zero, correlation to performance these days. 
 

With a few exceptions, I’d think really good sounding stereo hasn’t Earth shatteringly changed in the last couple of decades. Delivery Systems changed, the way we deal with bits changed, but a really good rig from 1999 still sounds like a really good stereo. A Jadis Defy 7, a dCS Elgar Plus...etc. I’d imagine it all still sounds pretty good. Why wouldn’t it?

I mean, a lot of preamps, for instance,  came and went along with a lot of technological marketing bluster but a Krell KRC HR (I don't even remember what year it came out) still sounds like one of the very best preamps I've ever heard.

@gents I tend to agree with you. Hi-fi has largely been a solved problem in the last 25 years. Implementation and personal taste are more important factors these days.

ARE you happy now ? Good now take your wife out for dinner....enjoy your find.