Sorry I pulled things so far from the workshop!

I tend to 'pick and choose' updates on my machines.
There's a big difference in my mind between an update/patch on Flash or Chorme and an operating system change (Win7 to 8/10, or MacOS X change). I'm more cautious about changing OS. So I understand Jay's comment about RAM, etc.
With Windows, I think the last successful operating system 'upgrade' I did was from Win 3.1. Since then it's always been building a new machine and installing the operating system 'from scratch' for me - not something I'll do without a reason.
I got back to using Macs again a few years ago and I've been pleasantly surprised at how well the OS X upgrades have gone (from one of the 'lions' through Mavericks to Yosemite). I've moved my non-tech family members to Macs and they mostly just keep working with fewer calls to the me (aka family computer help line).
WAIT!! I'm not trying to start a Mac-PC debate!!! ;-)
Did I tell you about the surfski repair I did this week?
;-)