I like the forum as it is. But I can see value to a few other features as well, so I'll offer my 2 cents worth about a couple of others I use (and comments about what I like about them or dislike).
WetCanvas (an artists' site, with forums and other things)
http://www.wetcanvas.com
This particular site is set up more complicated than I like... too many channels. But I do like the way it has easily separable sections for News, Events, Classifieds, and Forums. (I think the software that drives it could be used in a way that keeps the setup simple... i.e. keeping the discussion forums from fragmenting into too many "channels" and categories, can kind of fragment things and make it harder to find things... i.e. what Gina said above in post #7. Though wetcanvas has that kind of fragmentation, I think the software package that drives it can be set up simply... it's not a function of the software driving it so much as the way that particular site was set up).
TheSamba (an aircooled Volkswagen/VW enthusiast web site, with forums and other things)
http://thesamba.com
This site is set up very nicely. It has forums, and allows categories for forums (defined by the administrator though, so that the categorization doesn't get fragmented willy nilly... it stays stable). One feature that I particularly like on this site is the Search function... it is set up in a way that fits the basic taxonomy of the site pretty nicely (a nicely tailored search function)... and it allows Saved Searches (favorite searches) to be stored in your profile. (Only you can use your own saved searches... there's a non-public part of the profile). The overall profile function of this site is pretty nice... it allows saving of several different kinds of site object in the profile (I can save references to particular ads, I can save searches, I can save particular posting references, etc.). It also allows the categories of content to include other things besides forum threads (classifieds, news, reference sections that are pretty nicely done). It also is arranged to keep the reference materials integrated in with a number of options for easy header-bar links (i.e. a header that reflects the site taxonomy or "site map"... you can link to any of the main sections of the site by clicking items from a menu bar across the top).
Overall I like the layout of this site (thesamba) pretty much. Plus one feature that I think is very important: I believe the software package driving it is very simple for the site administrator / moderator to use and manage. (This opinion formed from correspondence with Everett, the site admin/moderator, rather than from personal use of the site management software package). If true, I think that's an important consideration for Jon's use.
Figs4Fun (this fig enthusiast site).
http://figs4fun.com
This one is great because it is so active... a very active community here! Though I miss a few of the features above (like saved searches, or easier navigation to reference parts of the site), this site has more of the "community" sense than any of the others I use. That may be partly because of the size (e.g. wetcanvas and thesamba each have over 250K members), but I think it's mainly because of the enthusiasm of the members and moderator here on figs4fun.
OK, that's more than 2 cents worth. Good luck Jon with your quest for site software alternatives.
Mike central NY state, zone 5