I used to play on my Anbernic RG351MP. Honestly, the only thing about it that I disliked was the screen size, but otherwise it was so good. It brought me back to playing on my Gameboy Advance as a kid.
I recently upgraded to a Steam Deck for emulation and integration with my Steam library, and I'm really not a fan of the Deck's super loose dpad. The sticks also make my thumbs numb or something. There's a huge concave dip in the center of the sticks and the outside of them are really kind of sharp. The sensation is not comfortable to me at all.
I ordered the dbrand Killswitch and thumbstick covers, will arrive hopefully within the next few weeks. Stuck at customs right now I guess. Those are honestly the only complaints about it that I have, though. Otherwise it's genuinely the best game related purchase I've probably ever made.
I don't have anyone who would actually appreciate the RG351MP in my real-life friend group or even in my online friend group. If anyone wants this thing, it's still in great shape and I've got a huge selection of ROMs with 351ELEC installed. I'd be willing to trade it or sell for super cheap.