IMO this is all smoke and mirrors.
I have an MTN contract that I have to renew at the moment, and no matter how I do the calculations, I cannot get within 50% of the cost of the previous contract - this is if you factor in the value of the included phone.
These new contracts just don't work for me, there are no additional benefits, just a huge additional cost. If I look at some of the evaluations above, they all leave something out, be it the value of the phone, or something else.
The contract has expired, but for the time being I am continuing with the old minutes-based contract on a month-to-month basis until I decide what to do. But it looks as if a transfer of the phone number to VC is the answer.