I love Toodle-Do and make heavy use of the ability to sort tasks by Importance, and also of the Scheduler function.
It would be fantastic if Toodle-Do Scheduler could cooperate with Outlook Calendar in such a way that it could block out time for each task (around existing Outlook Calendar commitments, and scheduled for each users' working hours - which they'd have to provide in advance obviously) and possibly flag up if there "aren't enough hours in the day" - ie there's not time to fit all tasks in ahead of their deadlines...
I know - a massive ask in terms of development, but it would be a massive leap forward in terms of productivity.