In reply to Matt.

Yeah, I feel ya!

I manage about 50 Wordpress sites (for a total of 250 sites using WP/Joomla/Magento/etc. across 10 dedicated, self-managed servers). Keeping up with so many sites / servers (by myself) can be quite the task.

For Wordpress, I use the "Advanced Automatic Updates" plugin. This helps a lot, but software updates (in general) aren't perfect. So I still check each website to make sure they are operating correctly after each update.

And of course, automatic updates only go so far. There are plenty of commercial plugins and themes that require manual upgrades (i.e., Themeforest / CodeCanyon).

My experience with MultiSite:
A few of my clients (the ones that have a lot of domains) use Multisite. It works pretty well, but MultiSite installations themselves have their own set of issues. Generally speaking, I try to avoid having everything "under one roof", unless the sites are 1.) for the same client, and 2.) very similar in functionality.

I'm open to suggestions. :)