I agree with one of the previous replies of not understanding the hate for Astarion. I think he's underrated. If you choose to keep him, he's actually pretty useful when it comes to fighting. Keep in mind that Larian has said that your choices will have consequences in the game. Once you find out that Astarion is a vampire when he tries to feed on you and you let him, he will gain a pretty powerful ability known as Vampire Bite. That ability will take away about half of an enemy's life. He's also good at the backstab sneak attacks and the powerful range bow, he also gets some type of magical abilities. I haven't unlocked all of them. I have done a lot of critical hits with Astarion, although because he's a rogue he is weak against magic and heavy warrior hits.