Been using Amazon's generous return policy to try out some of the Anbernic emulation handhelds. Have gotten more than what I ordered due to being sent the wrong models, but used that to my advantage for more testing! The stock firmware that these things ship with is super-dated and kind of janky for certain things. Some units also lack sleep functions. Fortunately, all of this is easily fixed with custom firmware, which not only improves functionality, but even improves video quality and some performance with newer emulators.
RG350: I was sent one of these instead of a 280M. It's kind of crappy. Build quality is OK, but the buttons and d-pad felt like garbage. There are newer RG350P and 350M models that improved on this a lot. The only reason I even tried this was to see how HDMI-out was. It wasn't very good and had no options for screen size (everything was stretched out to 16:9), some emulators didn't work right with it, and the sound still came from the handheld. If this is what Anbernic was putting out 2-3 years ago, they have really improved A LOT since then, although the HDMI-out isn't any better on newer units. They removed HDMI-out entirely on the 280 and 351 lines and it really doesn't matter.
RG280V: This is the first one of these handhelds I got. Decided to try this one because of the video below. That guy's channel and site has a lot of useful information on all these devices, BTW. Made putting custom firmware on them a snap. The 280V is a *tiny* handheld that lacks an analog stick and is not the most comfortable device to hold (it's a bit too small and the shoulder buttons are awkwardly-placed too high up), and yet it's just so cute n' cool, lol. Once you flash it with ADAM firmware, it's a
really snappy device and the picture is surprisingly good. It works best for 8-bit systems, Genesis/Sega CD/32X, and SNES, arcade, and PS1 games that don't need more than four buttons. This is by far the most "pocketable" device and is super-light and easy to carry around.
RG280M: This is basically the same as the 280V, but with a horizontal form factor, an aluminum chassis, and a single analog stick that looks and feels like a Switch stick. Performance is the same, but the device feels much more premium and is more comfortable to hold and use. Is overall my favorite right now. It's just the right size and the quality is really good overall.
(I did not get this color and opted for a silver/metallic finish instead!)
RG351MP: This is the newest out of the units I tried. It's also got the same premium, all-metal chassis and uses the same larger 4:3 screen that the O.G. Gameboy-styled RG351V uses. Basically it's a mash-up of the RG350M's shell and buttons with the internals and screen of the 351V. There is some noticeably better performance and platforms like Capcom's CPS3 run perfectly on this, whereas those games don't run at full speed on the older units. Disappointingly, some other arcade games that didn't run well on the old units, like Asura Blade and Asura Buster, still run poorly. This can also run N64, DS (although it only displays one screen and there's no touch functionality), Dreamcast, and PSP games, but a lot of the performance leaves a lot to be desired. Some games will run well, like Ridge Racers on PSP, but then something like Crazy Taxi 2 on Dreamcast runs at sub-30 and is extremely choppy. I wouldn't buy one of these for those platforms. I wouldn't buy one of these at all, in fact- even though the hardware is better, you just can't beat the ADAM custom firmware, IMO, and it's not available on the 351 series (at least not right now). For the price the 351MP sells for, you can get the newer Retroid Pocket 2+, which has much better performance, plus HDMI-out.
Overall, from what I tried, I think one of these units is worth picking up if you want to play anything 8-bit or 16-bit, (most 2D) arcade games up through the 90s, and most PS1 games. Anything beyond that may not run well and the newer devices aren't worth paying extra for. The 280M is my pick for the best one, although I am going to keep the 280V, too, because it's just a really cool little novelty. Also to note, while the d-pads are good on these things, they're a bit too stiff, which can be a problem for fighting games and some arcade games. Fortunately, the analog sticks work really well as mini joysticks. Something to consider when looking at the 280V.
Something to also keep in mind is that these devices come with cheap, crappy micro SD cards that are prone to failure and may not work right out of the box- if you get one, make sure to use a reliable micro SD card. You can use a 16gb or 32gb card for the firmware and then a larger card (128 will hold a LOT of old games!) for the ROMs. I recommend getting a 350 or 280 series unit because of the ADAM CFW. ADAM is not only very fast and reliable, but the emulators are also all pre-configured with the best video settings and filters. You can just pick up and play without having to do anything.
I might try the Retroid Pocket 2+ whenever sellers start offering them on Amazon (need that no-BS return policy), but I don't really need it since I have the GPD Win 3, which outperforms all of these things by a country mile. Was interested in these devices since they're much smaller and lighter in comparison.