I left AT&T back in 2012 or so when they started to flag and reclassify my plan on every import model I bought. Prior to that, T-Mobile was almost purely urban

I left AT&T back in 2012 or so when they started to flag and reclassify my plan on every import model I bought. Prior to that, T-Mobile was almost purely urban and AWS band supporting phones were a little obscure. But that's not an issue today and now I can import whatever. I still have a few active SIM cards supporting GSM-only operation if I feel like using an old phone from 2005. (I have a sony ericsson w810i that Google's WAP site still works on, the oldest phone I tried within past year was a t68i but data wouldn't work, just calls/sms)