Please don't compare this to the Zen, it most likely absolutely slaughters it in every conceivable way (
https://www.audiosciencereview.com/...ds/ifi-zen-dac-and-headphone-amp-review.9885/). "For $200 you can get a DAC and Amp combo that would run circles around it." That was 2 years ago, Topping has upped the game substantially since then.
This seems endgame for the vast majority of headphones. Even if for instance I had something like the Stealths, I probably would still get this. No one needs balanced and it can be a detriment (ref Benchmark's paper on this)... it does allow more power on power limited devices such as dongles but the single ended output here is more than sufficient. Only super hard to drive headphones that benefit from a crazy amount of voltage swing may benefit from more.
Yeah having a 1/4" jack would be convenient, aside from that, it likely will be an instrument grade device just like everything they've put out lately.