Graphical improvements not withstanding, the frame rate on the PC makes it the clear winner, but I'm on PS4 and it still looks great and performs well in most areas. 60 FPS on PC is so nice looking. On PS4 occasionally frame rate can get kinda iffy during busy, swamp-like areas with lots of effects. The main game is 30 FPS on PS4 with some things being 60 FPS I believe (such as Geralt's model on the inventory screen). Around 3 minutes in when the fighting starts is when it's most noticeable.
My PC would need an upgrade to be able to run that well though and video cards are expensive. Definitely don't regret buying this fabulous game regardless!