personally i prefer not having to learn new keyboard shortcuts to style a todo list for example as that first video discusses. i just write it out, use an asterisk or some easy system to show points, outline levels or whatever. if it's important to get done that day i note that in plain text. this is faster and easier to remember than learning a whole system for todo lists and marking up the different items importance, etc.
i want my email client to be focused on email, and a scheduling or calendar program to be focused just on that. for me bbedit is a swiss army knife of text editors in that it does lots of things to text - grep, search over huge numbers of directories, whatever. but i don't want one environment for things beyond that. for me those do many things badly, instead of one thing well.