T-Mobile recently improved their roaming with Magenta and Magenta Max. We upped our Magenta plans to Max for one month. The high-speed data did work for 5GB then it dropped down to 256K. I could not get more than LTE/4G in Italy even though I have an iPhone 13 Pro. It did show 5G when we connected in Germany though but by that time I was down to 256K.

Roaming was okay. I seemed to have more problems than my family using iPhone 11 keeping a regular connection with my newer iPhone in Italy. I would often show no service when they had it and I'd have to go to airplane mode and try to get connected again.

I was curious how 256K was and it was definitely useable if you are using Google maps, data message applications like iMessage for text messages, general surfing, and data voice calls. It was very slow at sending photos in iMessage so if you are planning to send photos at 256K be very judicious or you'll lock up iMessage waiting for it to be sent. It also did not like Apple Music. It seemed to be okay with YouTube using low video like 240.

I am kind of torn about 256K - works great if everything is going as planned, but when you need data fast in case something unexpected comes up, it probably will be painfully slow. We had some unexpected transportation snafus on our trip and am glad that one of my family member's phone had a local SIM in it. It's great that is in included but there are some potential negatives depending on situation.