It's all IEM/CIEM dependent. Z-R already comes bundled with a premium BTG-Audio Starlight SPC cable terminated with 3.5mm trs connector, as you can see in the picture. I tested this combo also with my TWau v3 cable which is bal terminated with se adapter (refines the sound, but with Z-R falls into category of diminishing returns unless you have unlimited funds to spend
). With Z-R + TWau v3 in particular, while testing SE vs BAL the only advantage of balanced output is a power boost and a little wider soundstage (depth/height are the same). Z-R is holographic-wide to begin with, and pushing it further makes imaging a bit distracting and not as natural. Also, no need for extra power, Z-R is efficient. Thus, SE output is just perfect and I can stick with a stock cable. Btw, using mp3 (320kbps) and FLACs for testing. With DSD128, I can hear some improvement in resolution while listening from bal output, but I only have a small handful of hi-res audio since I mostly listen to edm and top40 rather than classical