You should wait until three months until after the first major update. That is my simple policy for new operating systems. Here is my detailed reasoning:
- HARDWARE – When a new operating system drops (macOS 10.12 Sierra, Windows 10) it will likely break support for a lot of your internal hardware as well as external peripherals. This gives you more than enough time to figure out what will work and what will not based on the experience of early adopters. It provides manufacturers with the time required to update their own software and drivers for compatibility or at least give you the impress that they have dropped support entirely for your hardware. A great example of this is the Windows 10 blue screen of death whenever an Amazon Kindle is plugged in. That is not a critical piece of hardware for most people but it is still likely not something you want to have to find out the hard way if you wish you use your Kindle.
- New annoyances – Whenever a new OS is released there is a horde of techno-crybabies who will deride absolutely every change made to their experience, despite the fact that people often demand change. Waiting until after the first major update to the OS is a big deal as companies often simplify, clarify or even completely rollback changes made to the User Interface or other aspects (Microsoft frequently does this as their user-base is incompatible with any changes to their experience since 1992, why is 16bit support still going guys?!?!).
- Software – you know how it goes, right? You install the latest OS build and suddenly you are seeing an error when trying to launch some classic video game from 1994 or some critical medical image viewing application no longer works the way it should. These could be deal breakers for you, at least for a while before you have to upgrade to the latest OS.
- Security – All new things bring with them new problems, and security problems are always the worst. When Windows Vista came out, it brought with it a new network stack that was actually pretty great but had a new set of flaws (that shockingly resembled problems we saw with the “old” one…)
I know that these should be very obvious to you all by now but if you must have a policy about upgrading to the latest OS, you can borrow mine. I do insist that you install all of the updates/patches for your current OS once you have settled on it though and that you only use an OS that is still being maintained, if even just marginally. I also suggest that you always move on to the latest OS out of security and support concerns. You can always run a Virtual Machine of older OS environments if you must.