Update 14/04/2014: Here’s another one for the record.. A few days ago it was discovered that SharePoint 2013 SP1 had a bug and Microsoft has removed it from their website with a notice:
We have recently uncovered an issue with this Service Pack 1 package that may prevent customers who have Service Pack 1 from deploying future public or cumulative updates. As a precautionary measure, we have deactivated the download page until a new package is published.
If you happened to see my older post with links to the Service Pack 1 download, you would get a “We are sorry, the page you requested cannot be found” message when you access the SharePoint 2013 SP 1 page.
Well, its happened before when service packs and updates have been pulled back because of some serious issues. But after all these years, nothings changed. Maybe a hint to go SharePoint Online – you wont have these issues maybe?
Anyway, for On-premises deployments, I always recommend you wait for known issues, usually a month or so to know of any bugs and then make a decision on testing it out in your non-production environment first.
SharePoint 2013 SP1 is a fine example of what can happen to stuff that gets sent out by the testing team at Microsoft. This time, it was just 1 month of them releasing SharePoint 2013 SP1 when the bug was discovered, so may be waiting for longer like 2 or 3 months before you install any new piece of software on your farms would be advisable if you value your time and aim for a stable environment.