With the talking about how much time was saved, I was curious, so since I was feeling a bit shaggy, I decided to time it to see how long it took me to mow my head, face, and neck. This is without the benefit of having someone who can look over to see if anything was missed or do the back, so every part of the skull if probably gone over a few times, just to make sure.
Total elapsed time: 7 minutes 4 seconds.