Almost all the old emulators and games should work - but only if they don't require wifi or accelerometer which the RG350/M doesn't have built in.
That said, there are some updates to some of the emulators that are highly recommended. Fear not! They look and behave the same, so you shouldn't have any reason to be leery of them.
In terms of build quality and LCD, the RG350M is such an improvement over the GCW0. I doubt you'll have any regrets about selling it after you get it.