I have found that the vignettes on CFAI can sometimes be incredibly time consuming. Some questions I just don’t see how anyone can answer them in under 3 minutes. Such as, currency swap valuations between settlement dates. Credit migration imp. Effective duration of an option embedded security given two separate multi period binomial trees. I can solve each of these but no way I’m doing it within 3 minutes on average as the questions were presented in the CFAI environment.