… here are two more views closer up.
Based on this visual evidence, Pro would seem the rather tougher sell. How about in the saddle? Would it outrun X?
My most telling headphones are the exquisite Raal-Requisite SR1a ribbons on Schiit's Jotunheim R amp. That's what set up for my first trial. X fed the amp by RCA, Pro by equivalent XLR cables. With two identical SD cards and one remote controlling both, I had perfect sync. One amp toggle alternated which one I heard.
Power by Puritan Audio Lab PSM-156.
Having played it clipped, sharp and bright fresh out of their shipping cartons, the requested 200-hour break-in did clean house some. Afterwards, RCA off X and Pro was identical. The Pro's XLR output then went further on resolution, bass articulation and overall dynamic guts. But if single-ended drive is your habit, keep it simple. Sign X and save. On the subject of house cleaning and to demonstrate and exploit the utility of these compact players…
… I moved things around to build a true bedside bonsai stack of our suddenly spare Soundaware 280A feeding the Jotunheim R balanced into the Raal.