I agree with all the points made so far.
I have a 2012 Mac Book air and it is running Yosemite 10.10.3.
I also have a iPhone 5 running the latest version.
It all works. I do like being able to send text messages from the Mac...

My phone now wants to talk to my Apple Watch, which I don't have and I'm unlikely ever to have.

The biggest issues I have are with Firefox, each time OSX updates it updates and then seems to take some time to settle down.


Peter,
66, 2016 Porsche Boxster S
No longer driving Tarka, the 2014 Plus 8...