Do you have any examples to show how to work with a lot / complex data?
And which of these options (get_post_meta or get_field) is better / faster in which situation and why?
Hi Kevin. We suggest checking out the ACF docs on the Flexible Content and Repeater fields for some examples on how to work with complex data. They might have what you're looking for.
https://www.advancedcustomfields.com/resources/repeater/
https://www.advancedcustomfields.com/resources/flexible-content/
Regarding performance, get_post_meta() will usually be slightly faster than get_field(), mainly because ACF has to run additional logic to validate and format the fields as needed. But when working with ACF fields, we always recommend get_field() so that extra logic can happen.