I agree with that. The Brett Dalton character arc is pretty amazing when you think about where it started and where it ended. I still remember the bitching and moaning in season one like it was yesterday. By the time he was done, I was super pissed he had to go!
One thing this show has done that few before it have, is introduce so many really cool characters that simply don’t exist anymore for various reasons but at one time were integral to the plot. Even better is that there are a handful hanging around out there that you just know you’ll see again and will make you so happy when you do, both heroes and villains and people somewhere in between.