I guess the value proposition here is whether or not it can run emulators well. Lack of physical triggers is the worst part of playing old games on a phone, otherwise this device would be perfect for playing on the go.
I personally don't see the appeal, for emulation I'd prefer a Windows or Linux handheld with an AMD APU, which Ayaneo also makes, so that you could emulate more modern consoles and at the same time play some games from your Steam library.
I'm honestly surprised that no other phone manufacture has gone the Xperia Play route and just made a gaming cellphone. I mean all these handheld emulation devices show that there's a market for emulation on the go and everyone needs a cell phone now, so why has there only been one phone that combines them?
The risk of being targeted by lawsuits from Nintendo and/or Sony is likely very high which makes that segment not commercially viable, and that's also probably why most retro emulation handhelds are made by Chinese manufacturers as China doesn't really give a fuck.
their other Windows handhelds do, but this one I don't think so as Steam isn't available on Android (Steam Link is another story as it's just streaming from your computer)