No experience with them or the Doners, but my understanding is that they're on pretty equal footing as the JOYO stuff. My JOYO Stereo Chorus sounds great, but is definitely noisier than I'd prefer, and for some reason it noticeably boosts the signal volume when engaged (or, it's neutering the signal when disengaged).
My JOYO Quattro Delay is one of the greatest pedals ever. I defy anyone to try it and not instantly fall in love with it. It's a mini pedal for starters, so it has a very small footprint. It's VERY solidly built, each of the 4 different delay types sound freaking fantastic and are very tweakable provided you don't mind the tiny little knobs. It is dead silent, no noise or artifacts. The Analog mode is to die for! At 60 bucks or whatever it was new, it was the deal of the century, and cheap enough to justify buying a second as a back up if you're paranoid about gigging a cheap Chinese pedal.
It's a bad motorscooter.
I used both JOYO pedals in this video. The JOYO delay does the heavy lifting. I synced the delay times on it and my old ARIA Analog Delay so that the ARIA was on throughout the song, but at a MUCH lower volume. The JOYO got switched off during the verses. Pretty much all the delay you hear is the JOYO.