Welcome to the all-new iMore Forums! - We're still moving some things around, so you may see a few quirks here and there, but we're working on getting things fully completed as soon as possible. For now, take a look around, and if you run into any major issues, please let us know in this thread!
If you use Outlook's Tasks, then use ToDo. It syncs with ToodleDo, which in turn syncs with Outlook.