This is an interesting IPB site. I don't have much IPB experience but I've been impressed with the search and the tags so far. The similar threads feature seemed to work well too. A design element which is simple and effective was the Ask! Tab. [Demo: GBAtemp ] I think this could be replicated with xenforo easily. Use Jake's Nodes as Tabs to make the Tab, and then some forums for the question categories, and then a template change for changing [New Thread] to [Ask a Question] They also have some version of "Alerts" which I thought was pretty good, not as good as Xenforo mind you. Their arcade has Angry Birds !