Wow... exploring Skellige is like a breath of fresh air after Novigrad, and really reminds me of the first dozen or so hours in Velen, wandering the countryside stumbling into all sorts of camps, dens etc. Rather than proper questing I'm just clearing off all the Witcher School gear upgrades, building up a fast travel network whilst I'm at it for later.
Novigrad looks amazing for a medieval city in a PC game, but the questing got really arduous and stopped me playing for a long time. It was lots of running through the same streets to end up in more cutscenes, navigating both the criminal underworld and political classes. Maybe my mistake was fully exploring and completing Velen before going there.