@miram -- the forum is (nearly) fully functional as long as the traffic is that low as it is currently.
A better forum software can not improve these weak points: 1\. Post of new users may be invisible for some hours due to moderation. That can be very frustrating for users. 2\. Some questions get no really satisfying answers, or answers come late. 3\. Some users don't ask really smart questions -- some maybe by intent, some maybe because they don't know better.