Just wanted to comment how insanely fast this software is. Awesome.
And we're not even on InnoDB tables yet, still MyISAM. Once that's fixed, and we're running a dedicated ElasticSearch feature (searches won't poll the forum database at all) to power that area, BP is going to fly like never before. vB was badly bloated and horribly coded, but it served us well as long as it could.
I've also been extremely careful selecting add-ons. Paying attention to queries added and HOW they operate. We're not running with several that I considered important early on because they simply weren't well written (no worries, folks, I'm letting the experts make those judgements). Most of those we'll be using add no queries at all to the pages most frequently loaded.
Also, all our images are now in the file structure. This is less important to people other than me, but BP's old database is currently 8gb. Our new one is 1.8gb.
Those vBulletin guys must be shakin' in their vboots.
They've lost basically every big site (over a million posts) they had. Two of the largest (13 and 16 million posts) have come online in Xenforo over the last month or two, and another will be doing so shortly. The current belief is that Internet Brands (the company that bought the vBulletin franchise a few years ago) only cares about it as a platform for their own sites, and that what they can get from the rest of the internet is just gravy. So who knows, maybe they don't care at all. Either way, I'd guess that fewer than 30% of their customers remain.