As a completionist, I had a lot of fun 80% of the time. The other 20 (Merlin trials, collectibles, Duelist feats and side quests) were far too repetitive and felt more grindy than anything. You honestly have to do them all just to reach level 40 anyway.
Story was fun but your decisions ultimately had little to no impact on the game. They could have went more Dragon Age, Witcher with that aspect. Game is still worth playing though.