vBulletin 4 and 5 are trashy, and the brand its self is in trouble. They've stopped innovating and more importantly, their management is so disconnected from the customer base that none of us (the admins here) have any faith in the future of the software.
XenForo is too different and bare-bones. In my opinion it's good for just basic discussion boards, like if you had a website and wanted to put up a little forum for some simple talk, but it hugely lacks in the "community" feel that vBulletin has.
That said, we know that we can't stay on vBulletin 3 forever, it's already showing its age and is severely outdated in both technology and in visuals/aesthetics. Our current plan is to upgrade to the last vB 3.x release (3.8.8) which is in the works and will theoretically be released some time soon. It's taking so long though that I've considered just forgetting about it and doing it all myself (the only thing 3.8.8 does is adds support for the latest versions of PHP and MySQL, which I could do without them, it'd just be more work.)
After that, we're essentially planning on "forking" this version of vB and using it as a base for our own software. Up to now I've/we've only been able to make subtle improvements and changes, limited by using plugins and editing templates with the knowledge that the next release would require us to revert them. After we've stopped relying on vBulletin's updates, I'll be able to modify the code directly. I've got page after page of features written down and outlined that have been requested on an off here for years, as well as a bunch of ideas of my own that I want to implement.
We're also going to completely redesign the forums visually, which is something me and some other h-staff have been working on on-and-off for a while. Basically the two things together are going to be treated as a "revamp", or in my brain I call it "PokeCommunity 2.0" haha.
Real life has been occupying me lately and as much as I love PC, it's just a hobby, and I can only afford to spend my free time working on this stuff. So it's slow going. But it's happening, it's coming, and it's going to be super awesome when it's here.