I've been a big fan of Things for a couple of years. The ability to manage tasks and projects across iPhone, iPad and Mac is great and the user interface makes Things a pleasure to use. However having to manually sync via WiFi is a pain and forgetting to do it before going out can mean the iOS app is out of date and useless.
I've been using Things Cloud Beta for a few weeks now and it completely transforms the user experience. Whichever app you fire up is current and wireless sync is just a distant memory. Tasks that are moved to today are also now highlighted, making it easy to see what's new and either accept or defer them.
Despite being a beta, Things Cloud feels fully formed and I hope will move out of beta soon. If you use Things I'd definitely recommend downloading the Mac beta app from the Things website and checking out the instructions for setting up Things Cloud.