I thought long and hard about this. And played a lot of systems. And I have to say I like it better to gain XP with bother my completing micro task to keep myself engaged in the story we are trying to tell. But at the same way I am torn by getting XP by failures. The idea getting XP by learning from your mistakes. Speaks to me. And then again I like what as a group we all level up with milestones. I know how bad it felt when one class would level up and you did not.