I've been looking at the Chinese Android/Linux emulation handheld scene for a few years now and while I think these things are really neat I've never bought one. They've always either been too expensive or too compromised/crappy with no middle ground.
The RG35XX H from earlier this year was pretty close- it had a horizontal form factor, Bluetooth, Wifi, a full set of buttons and analog sticks, decent build quality and performance that could easily handle everything up to PS1 (and could stretch just a little bit beyond that), and could be bought for less than 70 dollars. I hated that it had those in-line shoulder buttons a lot of these Chinese manufacturers love and I wished the screen had been just a bit bigger.
(To be fair, I wouldn't mind a device that could readily play DC, N64, PSP and even the Saturn, but that sort of performance seems to cost at least 130-150 dollars and would most likely end up costing about 200€ in Europe)
This new RG40XX H looks to be the exact same thing as the 35XX H but with a 4-inch screen and stacked shoulder buttons. If it's not horribly more expensive than the previous model I might finally end up getting one
I've been following these things on and off and they've really stagnated for years. Really seems to me like Anbernic keeps making 20 new devices with different form factors and random combinations of numbers and letters for names, but none of them can emulate anything more powerful than frameskipped PSP.
There is the RG Cube they just put out that seems to be fairly competent at PS2 and GameCube but that again costs a hundred bucks more than these budget devices