Apple, Please Phone Home
Seamless voice communications among devices is promising, but Apple's approach needs some shine.
Only one of my Macs, a MacBook Air, is running Yosemite. Even so, I've experienced the calling feature. Setting up IP calling takes little effort. All you have to do is click on the Preferences tab in FaceTime and enable iPhone calling on your Mac, then select a default ringtone -- that's pretty much it. As long as your iPhone is in close enough proximity to your Macs, let the calling begin.
Maybe this is Apple's way of keeping it simple, but hopefully this is a beginning and not the end. I trolled Apple and public user forums and found a good sampling of users voicing that they aren't happy with the feature. Rather, they simply find it annoying. This is a departure from the norm, since Apple of course is known for making its wares easy for and pleasing to users.
One source of user frustration is the constant ringing that occurs with Find Me/Follow Me functionality and soft clients paired to desktop phones -– sometimes the ringing continues on one device even though the call has been answered on another. Radio propagation doesn't always play well with synchronization and connectivity.
Apple has embedded the feature throughout OS so you can make calls from webpages, or while in Calendar, or from your Contacts, Mail, and other apps. One would think that being able to communicate how, when, and where you want and on which device is what everybody wants. But Apple has made a mistake, I think, in its all-or-nothing approach: either you get the calls or you disable the feature entirely.
Again, I hope this is a beginning and not an end to what Apple is willing to do. Irritating users is never a good idea, so Apple may need to step back, "phone home," and make some improvements.