**UPDATE**: It has an zh1901mp02c chip, which is a rebadged F1C500s.
Ok, so I got mine, and it is not a simple rebrand of the RS-69. Yes, it uses the same OS and emulators, so it has the same base compatibility issues (same ROMs not loading, and the same layer priority issues for SNES), HOWEVER, it does not use the same chip (FC100s), it uses a different chip which I have been unable to identify yet. As a result, it has better performance on GBA ROMs (it used to have random frame skips), very playable performance for the most part on Genesis ROMs (it used to have nasty frame skip, now it seems to run between 80-90% speed, which while noticeable, does not bother much), much less frameskip in Arcade ROMs (goes from somewhat playable to quite playable), and less screen tear in NES ROMs (goes from looking like the screen is made of sloshing water to almost unnoticeable screen tear (and I am quite sensitive to it). Add to that the fact it has 6 action buttons makes for better gameplay.
As no device is perfect, especially Chinese devices, here come the cons:
- The D-Pad is absolute crap. It registered 2 of 5 diagonal presses. I modified it by opening the console, and cutting the 4 tabs it had on the diagonal axis (no idea why it had those), then using moldable compound to add approximately 2-3mm to the ball pivot it has. The result is that now all diagonals now work, and the increased height of the ball pivot prevents pressing all 4 directions at once.
- The screen has a "bad" viewing angle. I say "bad" because it will only bother you at the beginning, and will be noticeable if you keep putting it to the side just to remind yourself how much you hate those angles. The thing is, it looks ok at the angle you are supposed to play. Not the best screen, but I have seen worse and much worse.
- The menu button is gone, and now you have to press the select button for a few seconds to active the menu to exit or save and load states. Add to this the fact that using this menu is the only way to save (it doesn't create save files for those games that save), and the fact that some games use the select button for some functions and it can be a bit of a hassle.
- There is no volume rocker, only a volume button that goes up. So you have to press it to go louder and louder until it goes mute, then gets louder again. And it resets every time you turn off the machine. I saw some circuitry that could allow for the installation of a volume rocker, but then you would need to change the ON/OFF switch. Ugh...
- It does have an indicator LED, but it is hidden inside the machine. So you cannot tell if it is charging, if it has finished charging, if it managed to turn on, etc. Now, this might not be a problem for some people, but I would have preferred the LED be visible.
All in all, it's not bad. But... at 18-20 USD, it is in Bittboy V3.5 territory, and for 9-12 USD more you can get a Pocket Go, which is a much better machine. As I have got it already, I am going to use it as a cheap handheld on the go. If it breaks, it won't hurt as much as it would if my Bittboy or Pocket Go died. The ideal price point for a machine such as this is 15 USD maximum. If you can get it for that price, I recommend it if you need something to use on trips where you fear a more expensive machine might not return from. Hopefully the advent of machines such as this will push back those NES clone handhelds back to their original 5-9 USD price points.
If you want to know about ROM compatibility, think it similar to those of the early emulators of the DOS days, aka Nesticle, Genecyst, and whatever it's contemporary for the SNES was. This includes not just ROM compatibility, but sprite and layers issues it may have had as well.
Also, never buy something hoping there is custom firmware. Chances machine will get custom firmware are almost nil. Only reason those machines that did get custom firmware, was that they had a derivative of Open Dingux to begin with. So if you can't understand the difference between that and how machines work, my advice is to stick to WELL KNOWN MACHINES THAT ALREADY HAVE CUSTOM FIRMWARE. As such, I won't test games of any sort, not check if any CFW will work on it, as I believe I have provided sufficient information in this and my previous posts for people to know whether they still want this or not, and am sufficiently satisfied with how it works.