I'm sure this has been answered here often (I couldn't find any threads), for a non-audiophile, movie watching lug like myself, how much better can a v4 861 sound then the 568v2?

Also, somewhat off topic. Can a v2 be upgraded to a v4?

861v4, DSP6000 (24/96), DSP5000C (24/96), Ensemble (1TB)