Depending on how well the theme is coded and how the plugins are being kept up to date, I think it’s a great feature for website maintenance companies or for multiple site admins.

I have already started using the auto-update feature for plugins and I’m always up to date (same day or next day updates), so it’s a pretty solid setup. Being a theme/plugin developer myself, I try to keep on top of all the plugins I’m using by always reading the changelogs and the upcoming (or deprecated) features. This way I’m not taken by surprise when a major update is due.