So many good points. Tasks vs notes; not everything needs a checklist, some things are just notes. Thinking "I'll do that later" is a lot easier than "I will select a date/time in a calendar popup to schedule a reminder for this task". Todo apps are ineffective if having them is more work than the task you are trying to do!
A quote on HN about procrastination has also made be add Red Dwraf to booklist.