[saltcured]

I was on an even older prepaid T-Mobile plan, and they stopped allowing the purchase of "data passes" entirely. I was also seeing call reliability problems in urban Southern California.

If you have a spare phone, I highly recommend a Mint trial. There is a 7-day starter pack, which gives you two SIMs and lets you test briefly with a temporary number and then reactivate on the second SIM if you wish to port in your existing number. But, I thought the $45 pack was so cheap that I used it for a longer 3-month trial, after which I was happy to keep it alive as my new main service.

You also have to think about whether you care to keep your old grandfathered plan, i.e. on a backup phone. I kept mine because I can keep it alive for $5/year if not using minutes. But, I imagine I may drop it some day if it cannot be relied on to actually place an emergency call...