The plans with unlimited space are notoriously slow, since you are sharing a server with often thousands of other sites that the provider is hosting. However, it doesn't seem like the forum is doing enough traffic (yet!) for that to be much of a concern.
One amateur observation I have is that (looking at the bar in the lower left corner of the screen) every time I click on a new page, that social media gizmo on the left spends a lot of time loading stuff from Facebook and Twitter. I don't know enough about it to know how that can be fixed, but there is a couple of second time penalty there every time a page loads to get that thing loaded.
Of course, it is good to be hooked up to social media.....