Things sure has quite a following! Personally I'm impressed, but hardly blown away. The UI is nice - vastly superior to other GTD apps - but there are definitely some missing and half-baked features (um, Teams...). My biggest gripe is the iPhone app. Pretty much a joke at $9.99. I feel totally ripped off. The iPhone app's feature set is severely restricted and syncing is totally boneheaded. There's no way to trigger a sync! One has to quit and restart the app every time one wants to sync - and even then it never worked for me. :(

If you're serious about a GTD app, especially one that integrates *seamlessly* with your iPhone, OmniFocus is your only choice. The GUI pales in comparison to Things, but the feature set blows it out of the water. I sincerely hope that Things evolves into a more full-featured application. Right now the lack of good iPhone integration is the deal-breaker for me. I see no compelling reason to use Things over OmniFocus. While the Things UI is obviously better, OmniFocus is the better app for people who are *serious* about Getting Things Done!

That said, I look forward to the 1.0 release of Things and hope that the iPhone client will mature into something actually useful --- instead of a $10 rip-off.