Ive been using OF for several years. The app just keep getting better. It has the right amount of complexity and granularity to control the sorting (and almost if not more important) the displaying of tasks (using custom perspectives) to make them "bubble up" to get your attention in smart ways.
The Mac/iOS versions of the app work really well together and in my experience sync perfectly using omnis own service.
The date picker for tasks in iOS could use a bit of work to be simpler and more fantastical-like (like the OS X version) but this is an overall great app.
Raghos about OmniFocus 2