Iorveth. I've seen people mention his route is more interesting and while Roche is also a cool character, I can't really support his ideals.
Can't say the combat grew on me, more like I started to tolerate it later on. I can tell one reason why I don't like it, though: the overly long, random feeling animations. I noticed there were some moments, like when the enemy was far away, when it always executed a certain attack (like the leap in this case).
But otherwise it felt random. Press the attack button, and Geralt does a random attack. Maybe he only hits the enemy with his sword, quick and nice, or maybe he'll start doing a completely unnecessary stupidly long pirouette attack. I dunno, maybe you execute the different attacks with tiny different stick/WASD movements, but to me, fighting just felt really unresponsive and loose.
I may be a bit harsh right now since the last action RPG I played was Bloodborne which is pretty fucking amazing.
e: still a month to go
i might do a roche route playthrough too before w3 hits