I'd like to join in on this comment.
I'm also visit much larger forums (about other things really) and they are indeed much faster.
How hard would it be to convert the database for this forum to a newer/better supported forum?
My main gripe is the search functionality. I'd think everyone would want more options than what is now available. It is crazy slow as well. I can put in a query and then go browse other sites for awhile and come back only to see it hasn't finished yet... and when it does it hasn't found anything. At least for aircraft, you should be able to put in "p-38" and get a list of threads about it (and it should be long since it's a popular plane), but there are zero hits for that search query. (I just confirmed that search, 33s for no results)
Also, allowing for support for more browsers would be nice too. I'm mainly a Safari user, and Safari can display most any page Firefox can, yet this forum doesn't allow it to have all the bells and whistles of the message composition. As proof that it can support it, I can change Safari's "User Agent" flag to Firefox and get those same gizmos that were previously kept hidden.