How easily can you distinguish between different DACs?

Your hearing is fine. Darko admits that if there are differences, they are very minor. Any sighted testing is going to almost always produce a difference, as it does with everything. Only blind testing is valid to accurately determine if there is a difference in sound. 

That’s interesting that you ask this @audiodwebe as I did an experiment just the other day.

My system is a high-end system (Vitus amplification, top of the range Boenicke speakers). I have two identical SOtM sms-200 streamers which I connected back to the switch with identical cables. I then connected each with identical USB cables to two different DACs, one costs $1500 and one $25000. I grouped the two SOtMs on Roon so that my chosen music played simultaneously through both DACs. I attached these to two different amp inputs and volume matched the input, so it became possible to flip between them instantly from the remote, in real time.

Before the start I would flip between inputs at rapid speed so that I had no idea which was playing first. I made notes.

The result was that I could not reliably tell which was playing as they both sounded identical. At one point I was convinced the more expensive one one was flowing more naturally and had the a more realistic timbre of instrument. But when I tested myself I could not reliably pick out the more expensive DAC.

My conclusion is to spend your money elsewhere in the system.

@duckworp +1

Similar to my experience and sage advice...

Hey, I already owned an OPPO 205 that you can use with MConnect. I purchased the Ayre QX-5 DAC/ streamer via the network card. I tested them back to back playing all sorts of different songs on Tidal and Qobuz. They sounded different but one was not better than the other. In fact, I liked the little more warmth the OPPO presented. I might try the OPPO 205 against a Lumin P1 or X1. Most of the time I use my BlueSound NODE into a Wired for sound reclocker into the OPPO. It sounds really good and I love using the BS App. My system is pretty resolving so I can hear a difference in components and cables very well. 

Hello audiodwebe!  Differences between levels of quality are easy to hear. I have several Chinese made DACS with good  reviews. The differences among them are subtle. I was able to get a discontinued Sony DAC for half price and it was immediately more relaxing with only a very slight loss of detail. With the Chinese DACS, it was clear that the rear wall of a voncert hall was made of bricks - that's detail!  The Sony (I'd like to give you the designation, but I am out of the home due to a flood.) sound was more relaxed, immediately more pleasant and I couldn't telll what the back wall was made of. Who cares?! Beautiful music is what I want to hear and I've got it. I have two versions of the Dragonfly and a German made Dac as wellm and a Furutec DAC in the upstairs studio, a very pleasant sound as well.

Cables are another matter. The match between the cable and the DAC is important. Some folks swear by a certain cable, but your results may differ. My experience is that the Zafino USB cable (from Canada) beats everything else (even the Wireworld Silver Starlight 7, which is very good) in my cable connection. It is not pricey, it is just a quality product.  Happy listening.