I've worked on many Rails apps that are still out there in critical spots. My gut feel is it has stabilized. The hype was well-founded; it allows dev velocity that I still haven't seen in any other environment.
I once worked on the integration of an existing Rails app into an existing C# webapp (both living side-by-side, kind of a split-application thing, but seamless to the end user). It was almost hilarious how many LOC the C# teams (!) were having to write for every LOC I (alone) was writing in Rails. Looking through their diffs, it seemed like they were reinventing fire compared to me writing `render :success if SomeModel.update(model_params)`.
I once worked on the integration of an existing Rails app into an existing C# webapp (both living side-by-side, kind of a split-application thing, but seamless to the end user). It was almost hilarious how many LOC the C# teams (!) were having to write for every LOC I (alone) was writing in Rails. Looking through their diffs, it seemed like they were reinventing fire compared to me writing `render :success if SomeModel.update(model_params)`.