[Megamoose]

I used Things heavily for over a year before recently switching to OmniFocus a few weeks ago. The first few days took a little rethinking but having read the GTD book I was actually somewhat looking forward to it. Like you, one of the first things I looked for was some way to create a "Today" view equivalent. Turns out it's actually fairly easy to create a perspective to do this. The main difference is that Things relies on the "today" flag to mark your active tasks, and setting a date on a task simply tells Things to automatically set the "today" flag on that date. OmniFocus is much more flexible in this regard, supporting both a flag option and a due date; and these two are very easy to combine into a unified view that I've come to prefer over Things' implementation.

As to why I switched, it really came down to the number of projects I have. Things just can't organize lots of projects effectively. On the CC forums there are plenty of people offering suggestions on how to do it, but the result is always a cluttered mess. Since switching to OmniFocus, I find I'm much more comfortable with where I am in all my projects and that nothing's being missed (and isn't that the point anyways).