I have used Checkvist (checkvist.com) and like it a lot for lists. I tried it as a Toodledo replacement (I'm a tinkerer) but it ended up being short in a few areas. But as an outliner and checklist maintainer, it's pretty robust (very strong keyboard shortcut support).
The issue I had was that when I e-mail a task to my list, I want to add minimal (hopefully zero) extra characters to get the task in a place with visibility. Visibility in my TD setup is my starred list and my inbox folder (".Inbox").
Since the developers are still working on a way to star a task via e-mail, my other option was folders and it was too cumbersome on my PDA keyboard to type "[task] *.inbox" every time. If I just put the task name, the task floats to the bottom of my All Tasks list and gets lost in the shuffle.
My work-around was to name my inbox folder "*". Now when I send a task to my list via e-mail I just have to put "[task] **" in the subject line and I'm good to go. The task floats to the top of my All Tasks list.
I hope this is useful for other folks who might be waiting on the "star task via e-mail" enhancement.