QSM offers everything quiz and survey-related you will ever need. It’s easy to set up, easy to use, with lots of personalization.

While I would want some more features (like default language instead of copying recent quiz so it has all the translations), it still offers A LOT more than other plugins from this category.

Addons are paid, but DB entries are well organized and easily accessible, so you can easily write your own plugins/scripts for example for answers export.

I’ve tested about 10 most popular quiz/survey plugins and none of them offered features like QSM.