Just to clarify, the old gallery was transferred but only the file structure as to not break 10 years worth of posts. What didn't transfer over are the attachments that were within a post. While a lot of the conversion we did was manual, some of the functions were part of the SMF-to-VB converter tool we used. Unfortunately the tool doesn't transfer attachments over.
At this point we're just happy to be off SMF (which is barely supported anymore) and on to VB, which opens up a lot more possibilities for the website. Tech articles can now live in the content area of the site AND in the forum, helping users more easily discover great write-ups. We're happy with where VB can help take the site. It's a supported product that is pretty much the industry standard. Some sacrifices needed to be made for us to move forward.