I've been using ToodleDo as a tickler for about 1 month.
The biggest problem I have with it is that I can't MANUALLY select a batch of items for editing. For instance, I have 10 items to do today, and I want to move 3 of them to Thursday and 4 to next Monday. I can't do that via a search. And manually changing them is a huge hassle.
This missing feature is such a big deal -- such a severe and time-consuming bottleneck in my workflow -- that I am going to start looking at other task-management systems this week.
It's ridiculous not to have this, especially in software that is otherwise so good. And ludicrous to avoid implementing it simply because of the interface's existing checkbox-completion feature. Figure out a workaround, people, and make it happen.