Yes, every upgrade or downgrade results in a new modem, and a new term commitment. I’d suggest ordering what you want to stick with for at least a year.
I love, love, LOVE Sonic and have greatly enjoyed my service for the last couple years. I was very excited to learn that Fusion IP Broadband was available in my area, and my location had the ability to upgrade to the symmetric offerings. I used the upgrade/downgrade service in member tools and opted for the Fusion IP Broadband FX1 service.
That's were things started to go sideways for me. AT&T apparently cancelled my first install date on Oct. 11, and it's been a month long saga including multiple visits from AT&T, and many calls and texts with the Sonic support team and lots of waiting. Today I was finally told that I cannot get the symmetric 50/50 service that I requested, although I am being billed for it. I also have received an increase on my bill for the modem rental, although I am using the same physical modem I have been using for the last ~2 years. That just doesn't seem right to me.
I still think Sonic is still the best option for me, but at this point I'm disappointed and frustrated.