PostgreSQL GiST index - how to decide whether to use buffering or not?

One of the PostgreSQL GiST options is to use build buffering . However, I don't feel that the documentation is helpful enough for me to decide whether to use it or not. I also found this presentation https://wiki.postgresql.org/images/0/07/Fast_GiST_index_build.pdf explaining buffering in detail, but I can't figure it out.

To complicate matters, I created GiST indexes with the default setting (buffering = auto), so I don't know if it is being used or not. I have a 15MB dataset which is a map (this is not that much, I understand the effects are minimal, but still I am interested in its effects), so I guess it is static data that can be loaded in bulk. - but is it buffering build bulk loading? If I'm not mistaken, one of the problems with GiST is bulk uploading?