I downloaded the retail version of RetroArch and the PSP emulator to both my old One X and the Series X last night. I only played around on the old One X version so all these comments only apply to using an Xbox ONE X.
- The FTF program works pretty flawlessly, though it took me a while to figure out the folder structure. I'm using Filezilla over a wired gigabit connection and speeds were very reasonable for transferring data.
- The standalone PSP emulator works pretty well on the One X at a 3X scale. I only tested one title but it ran well. It might go higher but I felt 3X was good enough.
- RetroArch took quite a bit of fiddling to get where I wanted it. I prefer the XMB interface so I had fix that and then the icons were all missing so I had to fix that too but after this it seemed to work pretty well. Again this was on a ONE X internal HDD. Some notes:
- I tried NES, SNES, and Genesis and all ran well, even with a CRT filter applied.
- File operations, as some have mentioned, are VERY SLOW on this. Expect to wait for several seconds at a black screen for even tiny games to load. Once they load they work fine. Hopefully this can be sorted in the future.
- Since the Xbox button now brings up the XB guide instead of RetroArch menu in order to quit the game or change filters, you have to go in and define a new menu hotkey combo for RA. I used L3 + R3.
- In my experience, if you have your games in .ZIPs, RetroArch will unzip them but doesn't erase the game file afterwards, making having them .zipped pointless.
- Many changes I made in RetroArch did not take affect until I closed it out and restarted it. They didn't take effect immediately like the PC version. So if you make a change and it doesn't seem to have worked, close RA and restart it.