I think I am on the same boat of many VB users. I started with them in 2008 and now I am thinking of moving. My VB has a bug that the support doesn't care to help.
So let's start with a couple of questions:
1- I tried to use your demo, but I couldn't use it. The demo is extremely slow. Is this normal? I hope not.
2- My Forum uses Brazilian-Portuguese language (pt-br) is there a translation in this language for Xenforo?
3- I use the CMS from VB. With the migration to XF all the information on my VB CMS will be lost?
4- Is XF compatible with Adsense program? or I need to use an add-on?
For now that's it.
I really hope that I will have a great experience using XF. Not only with the product itself but also with the support.