Todo.txt vs Omnifocus

Todo.txt can be edited in plain text and then displayed with neat styles.

Because todo.txt is just a todo standard with various compatible apps to edit it, you can update it from any device as long as it can edit text and you can access your todo.txt file

It's convenient to be able to access your todo list quickly via your programming environment so you don't have to switch contexts, and to have a separate todo.txt file per project.

Todo.txt lists can be edited in virtually every text editor ever made and accessed on devices that support Dropbox. The user community has also created a number of apps for dozens of platforms.

You can edit your lists using the command line (e.g., Terminal) via a supplied bash script.

You have full access to the underlying programming rules, and therefore total control over your task lists.

Has been extended to include most things people want, including a multiple of interfaces and app for all platforms.

Todo.txt automatically and seamlessly syncs through Dropbox.

The community has developed a wide range of apps that interface with the basic file structure. These apps vary in how much they accomplish, how much hand-holding they do, their level of glitz, etc. They range from plugins for an editing app like vim to stand-alone, platform-specific GUI's. So YMMV depending on what you use. (todopy is particularly nice, a Python program that has a "console" mode which provides a keyboard-driven GUI.)

Does one thing: to do lists

It runs on MacOS, Android, and Python (in the Mac's Unix CLI) -- all for free.

At a bare minimum you just need to be able to edit text, but there are many apps and advanced interfaces you can install on many devices to supplement your to-do list editing.

Omnifocus allows users to setup the "defer date" which can be treated as "start date". Tasks will not be marked as available until that date, which should help to focus on the "available" task only.

The forecast summary shows a quick digest of the tasks you have for the day. You can select any day to quickly see what tasks you have planned that day. For extra functionality you can connect with the iPhone’s Calender app, which allows you to also see any other events you have planned that day.

The Perspective section allows you to see an overview of the tasks you have set. It also allows you to set contexts or see things you have flagged.

OmniFocus 2 allows you to set up contexts for tasks in certain areas. This makes sure you never miss a task when you're out running errands and happen to be near something you need to do.