Both work fine, when they work fine. ;) The recommendation to upload the patch manually exists mostly because quite often, the download from ZCC fails for whatever reason. It also usually is much slower. One of the issues the ZCC download has ist, that it doesn't properly check available disk space.

I'm not arguing mrosen's comment.  Just wanted to mention that I have always used the ZCC download method and not had a problem.

#1 - Updates are normally released to SLD before they are automatically seen in the ZCC.

#2  -If you have multiple upgrade cycles to do, sometimes it's useful to pre-download.

Let's say you are upgrading from ZCM 20.1 to ZCM 23.4 which is 20.1->20.2->23.4, it will be faster to have 23.4 downloaded copy copied to your primary so you can import it after the 20.2 upgrade versus having to download it through the ZCC after.

As Ken notes, using the ZCC is just fine and how most folks do it most of the time due to its simplicity.  Item# 2 is the common scenario where I recommend otherwise just to minimize the time needed.

These responses are very helpful, I appreciate the insight and I've checked disk space, so I will plan to proceed to update via the System Updates page.

Thank you to everyone that replied!

That's fine, I use it often too. But if it fails (rarely, but happens), then I usually just try the manual method, and usually always works.