Yes, I take the same considerations into account and will get a local SIM if I'm staying in a location where I can use it more than a few days or if there is a vending machine at the airport with a reasonable cost. I have had misunderstandings and dubious sales staff helping me in the past. There was one case I remember about five years ago months before T-Mobile introduced the included roaming where I bought a Vodafone SIM card at Frankfurt Airport. The person told me it was €1/day for 1 GB and 10 cents/min calling to many countries, including to the US. I was staying about a month, so I loaded the card with €40 thinking it would meet my data and calling needs. Taking this information at face value, I used the card indiscriminately until I lost the data connection 3 days into the trip. I checked and to my dismay had a €0 balance. I went to another Vodafone store where the staff there told me that whatever I had been told at Frankfurt was wrong.

The T-Mobile plan works for me internationally, even for some moderate social media use/picture sharing. I save the heavy usage activities for when I'm back at the hotel, but it's gotten me through my travels for the last five years without having to buy a local SIM card. It has had a few hiccups, but largely I've found the feature works as advertised and allows me to hit the ground running, not even having to stop at the airport phone store/vending machine along the way.