Awareness seems, from a pragmatic perspective, to be more useful to help us navigate environments we're not too familiar with
The more we're familiar with how to do a particular action, the less awareness we need to do it
Predictability of the environment in relation to attaining a goal probably plays a role as well; things that require constant "adjustments" are at least psychologically more draining
See, that's the thing with me; I've got tons to say about action, but nearly nothing about free will proper :)