I had heard of esim for a while but never really looked into it until a week or two ago. I finally decided to make the switch to it on my Tmobile Iphone 12. I called up customer care, who then had to forward me to tech support. It was relatively painless but it did take about 15 min for the entire phone call. The rep just needs to know the EID of the iPhone to sort of “switch” your phone number from the physical sim card in your phone to the EID in the phone.
What are the benefits? Well after I did that, I could now put in one of my Xfinity sim cards into my iPhone. This now gives me 2 phone numbers in one physical phone. Why do I need 2 phone numbers? I mean it’s the same reasons why you want a Google Voice number. If say there’s a Chipotle free burrito code that is limited to distinct phone numbers, now I have quick access to 2 phone numbers. I can make phone calls using the 2nd number if I wanted to. Texting seems to be a little bit tricky; I haven’t figured out yet how to send a msg using the 2nd number, but I can easily access the messages TO the 2nd number. Another huge benefit is I can also browse the internet using the 2nd number as well, so if there’s a T-mobile dead spot, the iPhone can then fall back on using the Xfinity internet plan, which is great because it automatically roams on all those home Xfinity modems. If you wanted to travel internationally, now you don’t have to worry about swapping sim cards; just pop in the international sim card.
The main drawback now is that I can’t easily move my number to a different phone, but realistically, how often and why would you be doing that? You do have to be careful about upgrading your iPhone because Tmobile will assume you will want to port your number to the new iPhone (see previous Tmobile free iPhone promo.) Either way, if you have a spare sim card/line that you’re not using, the benefits of esim outweigh the drawbacks.