I suppose it’s only fitting that Whedon himself is a self-proclaimed Sondheim fan.

Found this on Wikipedia today, while looking at the Merrily We Roll Along entry, in the section talking about the poor reception of the musical on Broadway when it first opened:

In his New York Times review on November 17, 1981, Frank Rich said of the production, “As we all should probably have learned by now, to be a Stephen Sondheim fan is to have one’s heart broken at regular intervals.”

Sound familiar?