#46.........the neck is difficult and it takes a while for:
1) The skin to "get used" to the safety razor.
2) The user to get used to the razor, the amount of pressure required, the proper angle, etc.
My neck is tough to shave because the whiskers actually run in three different directions. To get REAL close I have to shave east-west/west-east......which endangers the skin over my Adam's apple.
If the Mach-3 works for you, then rock on...........however you are missing out on the cost savings of safety razors.