When comparing Casual vs TeamWork.com, the Slant community recommends TeamWork.com for most people. In the question“What are the best cross-platform task apps?” TeamWork.com is ranked 50th while Casual is ranked 67th. The most important reason people chose TeamWork.com is:
Tasks are grouped in task lists and can have subtasks. Each task list can be assigned to a particular set of users, aligned with a milestone and have notes. Each task in the task list can have a description, a start and a due date, attachments, priority, manually set progress, followers, dependencies, be assigned to a particular set of users and set to repeat. Each subtask has the same configurable properties except instead of the ability to assign people, subtasks can be commented on.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Tracks task dependencies using a graph
Pro Great to-do templates
Every to-do list & project can be saved as an amazing template that you can re-use in the future.
Pro Offers a high-level overview of projects
The workflow with dependencies shows where the things are at a glance. No more frustrations of how your project is going and who is doing what.
Pro Sync deadlines to Google Calendar
To-do items can be integrated with your day-to-day schedule using Google Calendar.
Pro Visual way of organizing your work
The workflow includes dependencies and shows you where things are at a glance.
Pro Offers lots of granularity in task management
Tasks are grouped in task lists and can have subtasks. Each task list can be assigned to a particular set of users, aligned with a milestone and have notes. Each task in the task list can have a description, a start and a due date, attachments, priority, manually set progress, followers, dependencies, be assigned to a particular set of users and set to repeat. Each subtask has the same configurable properties except instead of the ability to assign people, subtasks can be commented on.
Pro Each project has only the required functionality
It's possible to limit projects only to the necessary features so that unnecessary functionality doesn't get in the way and clutter up the interface.
Pro Good assortment of features
Gantt charts, calendar and an easy overview of huge amount tasks.
Cons

Con Price
At its cheapest level, Casual is $9 per month for two users and two GB of storage. The trial period is short and there is no free version.
Con Provides too much detail for small projects
Amount of granularity for tasks can be overwhelming for small projects or teams.
