Here is the thing, when It first came out, I did not have a nation wide plan I had a bucket of LOCAL minutes like 200, so one time I traveled to London to do some work, and I was going to use my phone but I decided to turn on the wifi calling feature, when I did, I phoned back home to Toronto and this time did NOT place the 1 in front of the numbers, and the calls were treated as local calls for me. The thing about when you are making calls over Wi-Fi is that the cellular companies can NOT acurately get your location information so they were treating it as a local call for me, so I actually saved money by using Wi-Fi calling that day, otherwise if I had not turned on the feature and made the call as a cellular call, the cellular network would see that I was outside my LCA and would charge me long distance rates when I MAKE or Receive a call.
The only thing I am confused is how does wi-fi calling work outside of Canada now? back when I used it on my honey moon in the carribean, I was able to make calls as if I was still in Canada and I still have my phone bill to prove it that I did not get charged long distance at all. Tho the big companies might treat it differently now and can probably detect its not a canadian IP