This post is partly in honor of my ten-year-old discussion of the same question for Fusion, some things never change:
If I am correct, these are a few facts about Sonic fiber service (whether re-sold AT&T or Sonic native):
-All fiber services include an integrated or separate IP-to-analog phone device ("voice gateway" or "analog telephone adapter").
-They are required so that Sonic or others can get access to the public utility infrastructure as another "utility".
-Those devices are rented to the customers for a monthly fee. (Wire maintenance may be included with that fee, but it is irrelevant to this discussion.)
So here are a few new questions:
-What model(s) of analog telephone adapters are supplied with the various Sonic fiber services?
-Are any or all of those models known to work (or to -not- work) with rotary/pulse dialing? (There are definitely a number of pulse-friendly ATAs on the market now.)
-If I sign up for Sonic Fiber service (likely the native Sonic one when it is available here maybe soon) and their stock ATA is not pulse-compatible, can I return that adapter, buy my own, and save the monthly fee?