Since you asked about 5 or more authors, this is important to keep in mind:
At six authors, the in-text citation shortens to ONLY the first author, et al. (Barring situations where that would make the in-text citation the same as another citation, in which instance the number of authors for both citations would be expanded until there was a difference.)
At seven authors, the reference section listing is truncated and only the first seven authors are listed, followed by et al.
I'm not sure much greater than 5 authors you were thinking, but this is important to keep in mind. Doesn't seem that being eighth is worth much.