Overall, I did enjoy his arc in the book, but there was a point that bothered me.
What he did after the arena duel. The act of challenging Amaram right then seemed a bit too immature for his character.
An excuse might be made that it was right after the heat of battle and he wasn't thinking clearly, but yeah.
Aside from that, I'm glad he finally showed us his 'witty' (for want of a less used word) side that he hinted he got from his mother. It was a nice changeover from his deary self in the first book and parts of the second.
I noticed he's also started to smile and went as far as grinning in the chasm chapters. I suppose we have Shallan to thank for both of these.