Personally I like them all, other than Astarion. He rubs me the wrong way...Never really played wyll but once and thought he was pretty weak, so he guards the camp.
As for the personalities this has been said sense EA went live,
Lae'zel, She is a lawful evil Githyanki, She is totally militaristic and frankly I feel her personality in on point, full of herself and confident, she don't dick around. I like that.
Shadowheart, I think she's a big sweetheart, I mean yea she can get fiery , with that said I like a woman with a backbone, and some fire to boot.
Gale, yea It could be worse, at least he is not Astarion lol
Karlach, Ive only killed her and sided with her a few times as well. Will see what I think when the game goes live.
To sum it up, its not a group of my best friends im on an adventure with, its a group of people thrown together by chance and fate and I can choose, AGENCY, greatest or one of the greatest gift AO gave us . Its our story our choice. May you fare well.