Donoreo
I wouldn't recommend that. That forum is owned and run by someone else, so adding to an existing forum is going to muddy both.
Another consideration is that Xenforo is close enough in appearance to this one, so it would be a parallel move with a probable total loss of administrative control, and this forum could possibly be at odds with that forum's administrative goals.
It is really only the software choice that needs to be different.
Imagine being able to view topics and thread titles in a left frame (currently wide open) and being able to easily view them either by:
All Discussions
Today
Unread
Unread "To Me"
Unread Today
and several other options (about 13) to make navigation easier. Also, a way to select numbered messages within a thread, go directly to the beginning or to the end. Forum stats visibility, along with visitors, number of members, text size increase with one click, and user controls.