Cheap generic upscalers add significant latency and worse non-consistent latency. It might be OK for a turn based RPG like Persona 3, but it will drive you mad for games like DDR, Guitar Hero or heavily action based games.
As I said the results were "ok". Obviously you would need to buy a retrotink or something similar to have the best results but all but the most expensive models are often out of stock.
The biggest issue is that some stretch picture IMO. The latency is greatly exaggerated IME. I just used an older TV with a built in good upscaler (newer TV have worse upscalers).
IDK, when I tried one DKC was completely unplayable. For some games it's very important. This has been a well documented problem with the cheap scalers.
They have other issues too and RetroRGB has a good video going over the problems:
Not all TVs support 240p over component either, especially from the late 2000s/early 2010s which means you can run into problems with some PS1 games on a PS2 or earlier consoles.
I am aware of all this. This is why I said that depending on the box it can be either total garbage or "ok". At this point any emulation is always going to be easier.
