When I think of productivity in this context, I am referring to the rate at which one can generate value.

Software itself has value (eg, a client-facing web service). Therefore an IDE, which may require an investment to get past the learning curve, can have a productivity benefit as it can make generating software (and thus value) more efficient.

Do notes themselves have value? I would argue not really. For the most part things like "life planners" / "task managers" I've noticed are highly intricate but require considerable upkeep to maintain. Time that can be used to actually generate value.