I've been using iOS Reminders now for several months, and I'm convinced it is at least as good as the options on Lifehacker's Five Best To-Do List Managers, with some unique features of its own. Still, I'm not surprised it didn't make the list. The power user's instinct when first setting up a device is to download a well-recommended alternative for many built-in features, including an email client, a browser, and of course a to-do manager. Give iOS Reminders a second look, however, and you may be surprised by its power and simplicity.
What Reminders is:
iOS Reminders is a to-do list that syncs through your iCloud account to any iOS device or a minimalist webapp, and many desktop programs support integration including Outlook and iCal. With the IFTTT channel, you can connect Reminders to many other powerful services as well.
Reminders has all the basic features you'd expect - categories, priorities, alarms with basic "repeat" options, location awareness on iOS, and sharing with other iCloud users via the webapp. Moving a reminder from one category to the next is drag-and-drop in the webapp, which is nice.
One nice feature is the Scheduled aggregate list. It shows only those reminders with due dates, regardless of which list the reminder is kept in. This is my daily check, and it helps when I accidentally file a reminder in the wrong spot.
The real kicker for me is the instant compatibility with Siri. The most worthwhile reminder is the one you take the time to create, and Siri makes that quick and easy. Voice commands can't control every feature, but they'll get you close enough so you can follow-up later when you have time to add details.
Getting Things Done with iOS Reminders
For me, Reminders works great as a Getting Things Done platform. Aside from my physical "tickler" file folders, Reminders is my main tool to stay focused and organized so I can always get right to work.
In is for new items that you haven't organized yet. Empty this every day.
Next Actions should all have date or location alarms and should be within a day or two. Spend most of your productive time here.
Set everything in Projects to repeat weekly, which serve to remind you to create actionable items that address your longer-term goals. Those, of course, go in "Next Actions"
Someday is for ideas you want to keep around, but don't warrant your attention until you have free time.
Waiting for items are either waiting on responses or have due dates further than a few days out. Keep many items in here so your "Next Actions" folder can be super-focused.
Working with this method, I always have a clear idea of what to work on next, a place to write down ideas, and confidence that nothing will slip through the cracks.
What Reminders isn't:
There are, of course, downsides. If an iDevice isn't part of your everyday carry, the effort to get Reminders on Android or Windows Phone is probably not worth the trouble to you. Reminders also lacks the more complex organization and multimedia options some competitors offer, and some features are device-specific. If you want to organize and share, you'd best do that in the webapp. If you want to create location-aware reminders, you'd need to use a mobile device.
As with any app, Reminders will reward you if you take the time to explore its features. Give it a try and see if it works for you!