Great ep. Not only is it a tremendous character development for Gunn but it's thinly vailed parable on prejudice. Demons are being hunted much like vampires hunt humans.
What I liked was Gunn choosing the mission. At first we are lead to believe that Gunn was running away from his past because of what happened to Alonna. He certainly felt conflicted but he was never really unloyal in my eyes which was part of the problem. Gunn wants to be loyal to his gang but he believes in the mission he has with Angel. He admits that Angel isn't his friend but he sticks with him regardless because his friends are following a different mission: killing demons for sport rather than protecting people.
What's up with Lorne? While Gunn's old gang was killing innocent demons, there were also vampires, baby eating monsters. Gunn certainly was no more wrong than Buffy, Angel et al, for killing a baby eating monster so why let creatures like that into you club? Lorne claims not to judge but as shown in subsequent episodes, he does. It's actually kind of shrewd in a way. If humans, and different demons are in Caritas, they are not out on the street killing each other. It's not a perfect plan but it's one way of limiting casulties if only for a limited time. Considering these demons seek sanctuary, maybe that says something.