Mergers promise better coverage, but the customer story lives in edge cases I watch for plan migrations that quietly change throttling or hotspot limits The second tell is how billing systems handle legacy discounts without breaking Reading sprint reviews surfaces recurring pain points around port‑outs, credits, and device unlocks When transitions are transparent, churn slows and support tickets drop If updates land as surprises, trust evaporates even with extra bars on the map The boring path—clear timelines and clean bills—wins every time.