1) Meizu produces the same 2VRMS(take a look to my screenshot above) if the load is lighter than 100ohm or so. S8 produces the same 1VRMS or about at 32ohm load. That's why Meizu non-pro has about 50mW at 32ohm, S8 about 60mW at 33ohm.
2) I didn't notice any problem with my Meizu non-pro at 44.1k tracks, if you'll give me more details I'll try to find out.
3) Meizu is better for the distortions figures in real condition i.e. when the DAC is loaded with headphones because S8, in that case, has a few times worse THD. At no-load condition(without headphone plugged in), Meizu non-pro has the same distortions as S8. That's it.
I recommend Meizu non-pro because it a few times cheaper and much more compact vs S8. However, as I can see, S8 has 2 buttons, $50 for each, and if you really need that, of course, my recommendation looks silly