Can a GTD system be too simple?

I was reading an article the other day on Lifehacker that showcased how to use Apple Reminders for GTD.  The idea was that it’s so deeply embedded in iOS and OS X, that users of those platforms should find it beneficial to use it for GTD-based task management.

This raised another question in my mind, can a GTD system be too simple?  I’ve seen ways to deploy Outlook, Evernote, OneNote, Gmail and many other systems for GTD.  One of the founding principles of a GTD system is that it should be easy to use, or you won’t use it the way you should.  But isn’t there a balance between complexity and a lack of features?

It’s no secret that I have a very clear idea of what features are important to me, but each person will typically have their own idea of what is required and what is extraneous.

How do you balance the simplicity and complexity that both add to the usefulness of a GTD system?