DAC Input Topology

I have a Holo May DAC KTE and all digital in is captured by a proprietary PLL (phase lock loop) circuit which uses a crystal Voltage Controlled Oscillator (VCXO) and discrete voltage regulators to eliminate jitter.  They make clear that all inputs are processed the same.  Is this the primary method used by most (all) DACs?  
I ask because I was previously convinced that I wanted to buy a steamer with I2s out.  I was under the impression that a great clock in the streamer would be passed to the DAC, but PLL doesn’t use the streamer’s clock.  My fallback was USB and the May DAC KTE makes claims regarding the quality of their USB interface.  In fact USB is the manufacturers preferred input.   Now I’m looking at the Aurender N20.  The selling point here is the OCXO clock, which is four to ten times more stable than the Holo’s clock.  Many find the AES, or coax to provide the best sound.  Those that prefer AES, does your DAC use the same voltage driven clock PLL design?  How does the Aurenders clock provide superior sound when the sampling clock is an order of magnitude less stable?   I’m trying to decide on if I’m buying a high quality USB, or AES cable.  Maybe both at some point, but budget only allows one at this point.