I have a couple of the older ones and they're still kicking along fine as kind. If you don't need anything super fancy, these are fine little boxes. You can even extend the storage on them easily with a USB hub and stick.
I recall the 1st gen onn. devices getting very good reviews, so hopefully they continue to be good quality. This is a timely post, because I just watched this Linus Tech Tips video warning about the risks of those no-name/off-brand Android TV boxes straight from China:
With really good options like this onn. box and Google's own Chromecast with Google TV, there's really no need to get any of these shady Android TV boxes.