When I was researching before switching it looked as if you could keep your grandfathered unlimited data, but that you could not do a mobile share plan and thus cannot get the monthly bill credit. My decision to switch was based on the following:
- in September I will not be able to pre-order the iPhone through Apple and do another 2-year contract as all third parties can only sell on AT&T Next now
- there is no guarantee that I would get to keep my unlimited data when switching to AT&T Next
- there is no guarantee that AT&T will keep unlimited data around, especially after the recent FCC fine for throttling
- if you can keep your unlimited data, then you cannot switch to a mobile share plan, and therefore do not qualify for the monthly bill credit
- the iPhone 6s+ 64GB would cost roughly $45.50/mo on AT&T Next, plus plan ($20 unl text/$30 unl data/$40 voice), bringing my bill to $132.50 before tax
- this would increase my monthly bill by nearly $40 over what I am paying today
- if I dropped unlimited data and switched to mobile share (which sucks for single line customers), with the monthly discount my bill would be at $107.50/mo, which is still about $20 more than I pay today
So, for me, if I want the phone on launch day (pre-order through Apple) and want to keep my unlimited data (not guaranteed), I will have to pay about $40 more per month come September. If I switched to mobile share and dropped unlimited data I would still have to pay about $20 more per month come September. Or, I could pre-order through AT&T and keep my 2-year contract and current rates, but risk their pre-order process and only get a new phone every 2 years.
Switching to T-Mobile, I was able to keep my monthly costs right at where they are today and get the latest iPhone every year. I have 3GB of data, most streaming doesn't count and if I exceed that I just drop to regular speeds. For $20/mo I could get unlimited data and still be better off than staying with AT&T. I am also giving my money to a company that appreciates its customers.
As a side note, I had been with AT&T for 13 years and they never really did anything to show their appreciation for my tenure, nor have they done anything to try to get me back. I suppose you could argue that they let me keep my unlimited data this whole time, but with their latest move on adding activation fees to AT&T Next customers and increasing it for regular customers a month before the new iPhone launches just made me even happier with my decision to switch.