Toodledo and Ultimate To Do List work seamlessly together. Occasionally the sync to the phone is a bit slower than I would like, but that's just those occasional Type A moments. I still prefer Outlook with the Add-In for my list manager -- I like attaching files and emails to the task, which cloud-based services can't do (confidentiality issues -- I'm a lawyer); but GSyncIt is working pretty well between Outlook and Toodledo. You did a lot more homework than I did -- thanks for the great overview.
Jim