What’s your take on why one over the other, and do you think you should include a redirect for one to avoid throwing a 404 page when the wrong one is visited/typed?
Yeah I agree with felgall, it depends on the amount of content your forums are housing - if you are discussing a unique subject exclusive to one forum, I would then just choose the /forum option; if there are many sub-forums within the Forum then I would choose Forums - For my own forum I use /forums because we discuss many different topics - the redirect is a clever idea, why not - makes me think I better do that myself :eek2:
I would be tempted to base it on the number of “sub-forums” you plan on hosting - such as we have sections like HTML and CSS, their independent and have unique posts for that “group” alone. If your forum will just be a single stream of posts with no category organisation then call it forum, otherwise it should be forums (by definition). This goes back to the days when forum software used to be like mailing lists where you just had one stream with no categorical organisation of content.