We recently purchased Xenforo 1.5. We're in the process of migrating our forums from vBulletin 4.x over to the new Xenforo install.
I've set up test forums and migrated user and board data over. Last night I tried a PhotoPost Pro migration and it created 100 categories, but zero photos were imported (even though the import process for photos took 55 minutes) and zero comments were imported (even though that process took roughly 45 minutes).
I received no errors, but the import took almost two hours and only seemed to have imported 100 categories which are empty.