I have 3 vb forums - one was 3.6.4 and I recently moved servers and upgraded to 3.8.8 (with a 5.0 license but wanted to keep the v3 look).
I had VBSEO 3.0 installed but wasn't compatible with the new php on the new server but had to upgrade servers. Was at risk of losing 7 years of high ranked keywords in google for
http://energeticforum.com
I read that DBSEO was supposed to be able to import the old rewritten urls from VBSEO and I don't think they ever dealt with vbseo because it was so old.
Well, the team at DBSEO (I paid for the install and import) and it worked PERFECTLY! Saved the day and all old urls in google and everywhere else work just fine. DBSEO perfectly imported the old VBSEO urls.
I recommend the software and their team to do the install - they were even willing to modify the code to make it work for my old VBSEO if necessary.
I'll be purchasing another lifetime license for one of my other forums, which is vb4.