We just changed from Mavericks to Yosemite 10.10.5.
The Capture One v9 photo processing version required Yosemite so I spent a day (and a half!) switching to Clover as well. Using a Gigabyte B75 for my wife in an HP case and I have the GA-z97mx Gaming 5/4770.
Microsoft Vista was such a disaster. We converted to Mountain Lion, as I happened to have a compatible GA board at the time. I usually lag 8-12 months on each major release. There is often not time to really pick up the information scattered throughout this site for a major upgrade until enough mistakes get made for me to avoid them. These are our only machines.
Once a major new version settles down and I have the time, I study like crazy, reading for a few days off and on to isolate key posts and tricks. For the Clover conversion this is particularly true as just one setting, mentioned in only one article fix an otherwise non-booting Clover Config file. It takes a bit of detective work to understand where you make a wrong turn.
One has to be sure to down load all Apple install and updates at time of release, otherwise you are stuck with the current release, as of now El Capitan. I just keep ready made sticks for each release 'on file' just in case.
Thanks to everyone for all their help!