Apple has the tendency to release a lot of updates all at once, and keep quiet for the rest of the year. As a System Admin this means network traffic to Apple's update servers spikes only once so often.
Before Apple released their Caching Service in Mountain Lion, this often meant making sure every user is looking at a System Update Server for their updates, or downloading the installers manually and making them available on our intranet. A lot of work just to make sure we don't have a hunderd users all downloading multiple gigabytes over the internet.
Since the release of the Caching Service, this has changed. Anyone on our netwerk who downloads an updates is automaticallt redirected to our caching service without any work by me or them. Brilliant piece of technology.
The only downside of the caching technology is the fact that the server only works retroactively. Meaning the first user who starts a certain download triggers the server to download the software, which then pushes that update to the end-user. The second, third, ... users who request the same package gets the package served over LAN almost immediately.
Since I work in an office environment where everyone starts around the same time, there is a chance that multiple users will trigger the same download at the same time, without it being cached.
So in order to give every user a great experience, I woke up a bit early this morning and remotely updated one device to Yosemite + all the iLife and iWork updates. this to make sure that when people got at the office today, everything would be cached for them.
Compare this to the old update system. System Update Service, or SUS, downloaded every package in advance. Which meant no waiting times for no one. I understand this isn't possibly anymore due to the Caching Server not only caching Apple updates but also Apps and Books, but I can imagine a future release where Apple downloads Apps and Books on demand, but where an administrator can turn on a feature that auto-downloads any Apple update. Since the Caching Server serves Macs, chances that every downloaded update package is used at least once is quit high.
Aside from this little detail, the Caching Service is one of these services where everything just works.