Hi there dbastin, this is a good question, the K50 is the pinnacle of server design and sound quality in the market today, I love the K50, and would have one any day of the week, but it came down to money and DAC compatibility.
I initially had a Triode TRV1SE DAC, the reason for buying it was the dual USB inputs, anyhoo another story, with the Triode the K30 was a perfect match for that DAC with using USB only. And it was all I could afford, I upgraded from a DX, which is now an end-point in another system.
After some time I picked up the LKS DAC at a great price, this DAC is a massive improvement over the Triode, with a huge bang for buck, and with all the extra inputs wanted to utilize I2S.
One of the great things about the K30 is the ability to upgrade it over time. Another reason for purchasing it.
So I added the S20, the K30 has a 12v out, so I ditched the SMPS and ran the S20 directly from the K30 power supply. This sounded great, but then as money came in I added the S60 to take the load away from the K30's power supply, opening up the sound thru I2S.
Does it sound as good as a K50 - no. Could I afford a K50 - no.
Is it close - yes. Did building it step by step mean I could afford it - yes. Am I happy with how it sounds - absolutely.
There is a big conundrum in hi-fi, that is buying equipment that renders other equipment in your system useless, buying a K50 obviously would be the way to go, as it covers all possibilities in output, however buying something that suits your system now, and that can be upgraded over time as your system evolves is a path that I have chosen.
It is for me a balancing act of finances.