@Tempest Iron Bull and Dorian is probably the biggest redeeming factors in terms of party companions. Personally, I tend to more or less ignore Solas and Vivenne when I have Dorian around.
Blackwall is alright. Not bad, nor good, just lukewarm. He does get a little more interesting in the late part of the game. Cassandra I think has the most growth of all the characters, and I do agree that Varric is not the presence that he was in DA2, which is a shame. And it would've been nice if there was another dwarf character beyond just Varric(personally I was hoping they'd bring back Sigurn from Awakenings, I really liked her).
I could go on a rant about how much I hate Sera, nevermind that you never get the chance to have her go through SOME kind of character growth. She has absolutely zero depth or growth, which only makes it all the more infuriating. Almost all the companions have some kind of crisis moment. She doesn't, and in my mind, that kinda makes her a pointless character.