Hopefully this isn't too controversial, but when it comes to DACs, I believe the measurements. I use Topping DACs, the Topping D50 and Topping D30.
I have A-B'd quite a few DACs and have honestly never been able to hear a difference. I have A-B'd the Topping DACs against the Modi Multibit, couldn't hear a difference (I owned it at one time). Burr-Brown, Sabre, AKM, doesn't matter, I cannot hear it. So, I go for DACs that measure well: highest linearity, dynamic range, and lowest THD+N, and you can get very close to the very top of all DACs at around a $300 price point. At least then I can see where my money is going.
The new Topping D50s is an excellent DAC from a measurements standpoint and it is very reasonably priced. Not saying that more expensive, proprietary, and/or boutique DACs are not worth their price, as I am sure much thought has gone into the engineering and build design, just saying that I have never been able to hear it. Still waiting for a DAC to come along that I can say "okay, that sounds better." Maybe it will happen for me at ZMFestivus in October.
When it comes to amps, it is a totally different story, because I can hear it! And typically, tube amplifiers will not measure as well as solid state, but there are easily discernible subjective improvements over solid state (for me).
If I am going to have second or third harmonic distortion in my audio chain, I want it to come from my beloved tubes!