Alan Sircom from HiFi+ posted a glowing review on the LINK II that may be of interest to you.
“First, it’s phenomenally well made, and not just ‘well made for the price’. The milled-from-solid aluminium clamshell case (looking and sized roughly like a Mac Mini which had a bit shaved from its side) is an unexpected bonus and helps keep the circuit within away from too much resonance and vibration. This anti-interference goal is clearly a key part of Stack Audio’s DNA, as a big part of the design is what the company calls ‘signal detox’, which includes a lot of reclocking and otherwise jitter-busting the USB signal, and a lot of buffering and EMI filtration of the USB data pathways. Proof of that… if you use the Link simply as a buffer between the USB output of a computer and a USB DAC, the sound of that DAC is improved significantly. It’s more upbeat, more focused, and more natural sounding. Granted there are other dedicated jitter-busters that do a similar job for less money in this context, but they cannot do all the other things the Link can do.”
Read more here.