I've been looking at RTM vs Toodledo again, and I've concluded that there is only one thing on the RTM side that keeps anyone there: Saved searches on the iPhone.
In RTM, it's ALL about the smart lists. The smart lists + the tags are the only feature that you ever hear about in RTM. Just look on their "Tips and Tricks" forum. If this feature were added to Toodledo mobile, the app would become twice as useful and the RTM users would not have anything holding them back.