It's nice to hear from elite players that mapping clubs isn't needed. I was not looking forward to doing that.
It's not usually misjudging the distance a club hits that trips me up. Other than not adjusting for wind and elevation as well as I should, it's usually some quirk of a particular hole that gets me--the slope of a green that I've forgotten about, holes that seem like they just don't play the yardage they should, holes that need to be played a certain way, etc. I got the Course Notebook recently, and I'm hoping it will help with that.