Gale: Thought he was a decently nice guy at first (I give a lot of credit for this to his voice actor), with some inconsistencies thrown in. But my views on him completely changed for the worse during Act 3 when playing as Dark Urge. I started to warm to him some more again though after seeing banter between him and Minthara.
Shadowheart: Immediately jealous of her voice. Wish Larian would have given an option for a similar high-pitched voice for Tav, but for some reason that was forbidden and only reserved for Shart.
Not much changed regarding my initial views on her. At first I thought she was made to be just a pretty face type character who is a little aloof, but have noticed a tiny bit more nuance to her character since then.