I personally enjoy seeing all items on my to do lists, what I’ve done and what I need to do. I wish there was a way to set my account to default “view all tasks” instead of having to select that every time I go to a new project’s list. I love the idea of customizing it to just see what’s left to do or only see what has been accomplished, but like I said, I wish I could pick my own default option for what works for me most often.