I’ve been using ToDo for years. I also have OmniFocus, Pocket Informant, 2Do and a few others. I keep coming back to ToDo. This app keeps getting better and better with each new version. What I like about is that you can have checklists and Projects, you can create a task for a phone call, email, etc. You can share the tasks. It really does blow some of the competition out of the water, especially with the Cloud subscription. My tasks are synced instantly between my Mac, iPad, iPhone and iPad Mini. The competition syncs but takes a long time OR they don’t have companion apps for all my devices.
It’s great to set up a project for say Vacation and then have the individual tasks needed to complete that project, and even those individual tasks can have a checklist. So say you have a task to pack your clothes, well that task could contain a checklist of all you want to bring. Each task in the project can have it’s own due and start dates.
On the checklist side of things I have a weekly task to go grocery shopping, that task is then set as a checklist and I just go in and add items to the checklist. I don’t forget things at the store anymore.
I am finding myself using ToDo as my main task application. I still have the other apps I mentioned on my devices, but I am using it more than them. I could have saved a lot of money since ToDo was the first iOS task app I purchased back when the iPhone 3G first came out. Don’t get me wrong the others are good and each one has features that I like better than others, BUT for overall ease of use and reliability, I have tried several times to just pick one of the apps and I have even stopped the ToDoCloud a few times, but usually just renew it by the time the subscription stops. ToDo Cloud is the best of the lot.