I find taxonomy useful, but I think Derrida is right that Searle was more preoccupied making SAT (and language in general) into a mathematical formula than the "art" of language. I think the only really crucial elements are: - locutions - illocution (act/force and [or vs] intent) - perlocution (act/force and [or vs] intent)

I find very little use teaching or using the 5 categories of Searle for interpretation of verbal or written speech acts.

I find studying a locution from illocutionary intent or perlocutionary intent more useful than Assertive, Directive, etc.

Hope it made sense and it was a useful answer! I still find it a fascinating field that is under-utilized because people try to make it into a programming language (a la Searle) instead of a way to understand semantics and semantic intent.