I don't have a good projects/todo system.
I use Google Calendar with the "agenda email" feature (it emails you your daily agenda) which works well for things I'm highly motivated to do anyway (e.g. call someone on their birthday, go to that party, etc.).
Calendar ceases to be useful for me when either 1) the todo doesn't have an intrinsic need to happen on a specific date, 2) I don't want to do the todo. I am optimistic that GTBee will force me to do these things.
Now, let's consider GTBee because I think the same "number of systems" issue applies. If GTBee doesn't allow freebies, I can't use it for tracking poorly thought out things. More detail. You might say that GTBee shouldn't be in the business of tracking non-commitments since it is a commitment tool. But I'd rather use just GTBee instead of GTBee and Calendar both.
I think in both cases I'm suggesting that allowing more flexible use of a commitment tool makes it more useful rather than less useful. In the specific case of pre-commit data points, I feel this way primarily because they are backed up by a real Beeminder goal which cannot be akratically edited. I'm thinking of it more like a planning tool than a secondary commitment engine. Because if I wanted to commit I would just use the existing Beeminder.