I'm certain I'll get loudly shouted down for this, but as a home theatre entusiast of many decades standing I'll offer my opinion nevertheless. In my experience, the better the chipset, the better the final image on screen appears, and yes, that means noticeably and visibly improved picture quality.
I'm not for a nanosecond arguing upscaling can even come close to producing an HD image - I still get a chuckle from various manufacturers marketing hyperbole reference "near HD upscaling" for their budget players!
But, in premium machines, jaggies reduction, deinterlacing etc are definitely
performed to a higher standard.