I've had my GH Calling feature working since last week...maybe Wed or Thurs??  I've had mixed successes.
I can hear everyone perfectly on my end!  My husband can hear me just fine on his cell phone.  My daughter and mother (1 wifi home phone, 1 landline phone and one cell phone) had problems making it unusable.  Today I called my daughter's wifi home line again (after sending feedback last week) and connection was good on both ends.  I  haven't tried my mom's phones yet but will report back when I can.  Making my first business call...well that didn't turn out well.  Called Walmart.  Associate couldn't understand or hear me.