Based on what we knew about the companions before the EA I fully expected to hate Astarion and like Wyll. Oh how wrong I was. I ended up absolutely loving Astarion and feeling quite meh about Wyll (I can see how others would like him tho). Shadowheart and Gale were also 10/10 in my books. Lae'zel was doing the gith thing well. My only worry is that some of the more evil companions will end up having a Sebille kind of 180 during their personal storyline instead of remaining their own characters (Shadowheart esspecially), but only time will tell how that's going to go.
As for them feeling like edgy teenagers first characters... I wish my first DnD characters had been this good :'D