....and....

At the end of the day your sitemap is "just a file" with the links to all the files on your site. It is one of many items on your good SEO/website checklist to do and shouldn't be ignored however.

The SEO guys may scream in pain here but there are lots of sites that rank fine without a sitemap because they are doing damm fine in other more important areas.

There are lots of automated ways to make sure that your sitemap is up to date and doesn't deliver bad results and once you automate it you should in theory be able to "virtually walk away".