Strategically speaking, from a marketing standpoint, I personally would introduce a small part of any/all feature(s) into the free versions and offer full functionality of the same features for the paid versions, OR, offer full functionality even on the free versions of software but only for the first week or so? Just telling you what I would do if I was in charge. I personally believe in paid software because you know (in most cases) there’s no E.T. phoning home in the background and selling your history to 3rd parties.