What does Asana do well? Asana does a great job of allowing you to see your projects at different views, fairly standard but they do this well. They've recently updated their UI which has made things even better. Integrations are Not lacking, it has great options built-in as well as zapier options.
What does Asana not do well? My only complaint WAS, they did not allow you to switch from a Kanban view back to list view, BUT they have since updated this an allow now to move between all views; calendar, kanban, calendar and list.
What do you wish you had known about Asana before using? I wish I had known about Asana long before I spent any kind of time on Wunderlist, Todoist, Google or any other task list app. Asana is the most robust while being the easiest to use with no missing integrations.
Have you used a competitor to Asana? If so, how does it compare? I have used them all and they all seem to fall short in some small area or another, like those little design changes that you can't quite identify but it throws off your rhythm, Asana seems to have found them all and made for a clean and powerful experience.