I am developer (about 12 years of commercial experience, more than 20 years of total experience). I was tech-lead of admin team on last big project for about 3 years.

I can administrate servers (about 9 years of commercial experience, about 20 years of total experience with UNIX administration, starting from school), but I hate that. My choice is to create copy of the server, then make changes and write them down, then test them on the copy, then apply verified solution to production server (see http://vlisivka.pp.ua/en/modern_administration , sorry for my English).

I even implemented my own run-book automation tool, which reads documentation and then executes steps in automatic or semi-automatic mode (I prefer Documentative Programming style).

I often prefer to develop script or RPM package to make change to the system instead of making changes by hands.