VM cloning VS scripted setup/configuration

Perhaps a question of ignorance but... I have long since documented the steps required to configure my servers (Apache, NGINX, Samba, Postfix, whatever). Reproducing a server setup is simply a matter of carrying out the steps one by one. My feeling is that most (if not all) could be automated via scripting. My sysadmin tells me this is not a practice of professionals (though he is far more Windows centric) and his preferred style is to configure and clone by using VM's or ISO's. How common is it for nix pros to have a script for bringing servers up to speed quickly? Development environments varying significantly, installing xdebug or whatever tools. I have multiple environments, a development server (installing my tools on Windows is such a PITA), a deployment/CI server, production servers, etc. It would be nice to create a series of scripts which could get the ball rolling, modify required conf files, etc...all done programmatically making change in the future both clearly documented and re-producible. What is your opinion on such a matter? Other than a lot of work to get started I can't say I see much wrong with this approach...