The biggest difference between this and PS3 BC (for earlier models) is that PS4 emulator actually re-renders polygons while PS3 did upscaling the whole SD image (though it was very smooth).
IIRC PS3 also did have PSP re-rendering emulator too but they didn't bother to make it big feature. I think Monster Hunter 3P was the only adaptation of it. (Some hacked PS3's had those feature enabled).
IIRC PS3 also did have PSP re-rendering emulator too but they didn't bother to make it big feature. I think Monster Hunter 3P was the only adaptation of it. (Some hacked PS3's had those feature enabled).