I did not even know this was a thing and now I am very intrigued. Do you have any experience with a PS1 setup on something like this? Is there one with a good quality PS layout to run PS1 stuff? Point me to the rabbit hole if you will, what do you even Google for information on this sort of thing?
What custom firmware do you put on it?
Also do you think these are dingers or used?
As a longtime CAG member, I know that CheapyD frowns upon discussions about emulation, and I don't want to get banned for going down that rabbit hole.
And since it's a pet peeve of mine when people send me PMs about such topics, I will simply suggest that you visit the RG350 system sub-Reddit or the Wagner's Tech Talk RG350 fan website below that is run by one of the world's foremost RG350 enthusiasts. More than likely, any questions that you have will be answered by visiting his site.
And I wouldn't pay attention to the product reviews. If someone complains because they see Chinese language on the box or in the instruction manual, they probably shouldn't have wasted their money buying one or their time ordering one.
But I will say that I have purchased other Chinese handhelds from Amazon Warehouse that were already tricked out with everything on them that I needed, custom firmware and all. Others were dingers brand new from the factory except that they were opened, and they became do-it-yourself projects. But I enjoy doing that sort of thing anyway. It's half of the fun.