YMMV / Stiffelio

• Adaptation Displacement: Long story short, the novel, play, and Italian adaptation are all out of print and the play hasn't been performed in God knows how long, but the opera is performed {albeit not particularly often, but hey it's better than not at all)!
• Audience-Alienating Premise: Audiences (and opera house officials) in Austrian-controlled Catholic Italy in 1850 were arguably simply not ready for a story with the social and religious ideas being advocated for in this opera, which is part of the reason why the work never really got off the ground.
• Esoteric Happy Ending: For some reason, a disproportionately large number of people who have directed this opera see the ending as an example of this, implying that they do not believe that Stiffelio and Lina can or will get back together after the end despite there being basically no evidence for this in the opera itself.