Bayesian or frequentist for the actual launch decision? I went back and forth on this longer than I'd like to admit. What settled it wasn't a theoretical argument — it was noticing how simple the Bayesian version could be, and then finding a genuinely surprising wrinkle once a second metric enters the picture.
Why Bayesian, in Practice
Doing this properly with a non-inferiority test is entirely possible, but it adds real complexity — a margin to agree on, a one-sided correction...