@Signor Amministratore My experience has been somewhat different. The reliability of #guppe does not seem constant to me. Sometimes it dropped out or a post was only shared hours later.
With a #Friendica #forum, on the other hand, I have observed a relatively constant latency of a few seconds to 1-2 minutes.
Perhaps @Μαθθίας/ξ ✔ can contribute something more competent.

In addition, a forum also offers a relatively well-structured presentation, while guppe is just a pure distribution list.