Today we've bought a licence of xenForo + RM and installed this at a test server. We decided to do it slowly, and we have read Brogans Importing guidelines and firstly like to play a bit, to get more familiar.
Due to, we have to migrate > 6 Million posts, we think, we will buy vBulletin Big Board Importer.
The question, I have now is, what will be overwritten by the importer? I think we can change templates, make a design and therefore add css-files. But probably, if we create a node-tree, should that be deleted before doing the first test import?