Ask HN: What's an Example of a Successful Rebranding?

There have been many rebranding in the past of big companies that have largely received a negative response from its userbase and the community at large. Examples include Slack's recent logo/color/design overhaul, DropBox and its new radical color combinations, Windows 8 and its Metro design language, etc.

Is this "backlash" over new designs just a user's reflex action to change? Or have they actually been detrimental to the company (due to mass unappeal)?

In continuation, what are examples of "good" or successful redesigns that were positively accepted by, if not all, a majority of the users?

Thanks!