Switched from party plan, so same phone and not new. Concern about new SIM losing things on phone. Internet mentions only effects text messages and contacts. (Wonder about apps,wallpaper.) Settings storage to Google found about contacts. Cannot figure text history. Some differences of SMS and MMS. Maybe different apps for texting. Not sure how to preserve my reading stored threads. Also, not sure if new SIM needs more capacity as I am at 22 of 24 when I update apps. On this 32 phone, I have option of external SSD card for adding capacity, but have not needed it before, but switching makes that another question as to if it uses more GB. Not a lover of change. Anxious.
As far as I can tell I didn't lose anything last week when I switched. If I did I have not noticed. I never paid attention on whether it needs more storage or not but I doubt it does. I am not sure how text messages are saved but even when I switched phones all my old messages were retained and somehow were transferred when Google asked me transfer everything from my old phone when I signed into my Google account on my newer phone.
The one change I have noticed is slightly faster speeds. I went from mid teens to mid 20Mbps to mid 30Mbps average. I happened to be up really late last night and checked since there can't be much traffic on the network in my area and I actually was close to 70Mbps. Just checked and got 43Mbps. Pings went from 100 to 140ms to around 40ms.