When I moved houses, my Verizon phones had poor coverage at my new home. ATT was the better coverage so I switched to Straight Talk on the ATT network and brought my own phones (high end smart phones). I just got on Amazon and found unlocked phones that worked on the ATT network. I transferred my phone numbers and things have been good since then. I have not traveled yet, so I'm anxious to see how that turns out. I was happy with Verizon's coverage in rural Utah (but for some reason in the populated area at my new home they had poor coverage).
One note with ST: If you are going to transfer a phone number, do not activate the SIM card until you are ready to transfer the phone number. I activated the SIM card to test ST before transferring my phone numbers but then I couldn't transfer my number without getting a new SIM. They seem to encode the SIM somehow and they can try to switch the number but they run the risk of bricking the SIM somehow.
I had to go buy another SIM to have them set it up again with the transferred number. It was a hassle so I highly recommend planning ahead.