Aviate navigate & communicate, funny how the spoken word is considered the last in the 3 major things to priorities. But when it comes to a busy time in a CTAF etc. I'm not so sure the above order shouldn't be reassessed.You don't all of a sudden loose control of the A/C (all things being equal), you don't all of a sudden loose yr way (nav wise) but you can all of a sudden become overwhelmed with what's happening around you in a busy CTAF App point just like the one we are talking about here.
So unless yr spiralling out of control the eyes & ears are yr best defence to stay alive at any GAAP.
The word "Busy" is explained as one EG..........'cluttered with detail to the point of being distracting'.........Both VFR & IFR can be 'busy', no contest there I believe.
Wmk2