Ok... now that both UBBv6 and vBulletin v2 (currently beta 3) are out, I'd like to bring up this topic again. I'm currently using UBBv5.45 on my site, and I was contemplating between updating to UBBv6 and vBulletin v2. As it stands, it seems as though vB has way more standard features than UBBv6. Sure you can achieve these features with hacks, but why hack if the standard version of vB contains all these features and more. Plus it's faster, and smaller. (Not sure how it compares to UBB6, but I'm pretty sure it's smaller than UBB5.)
So can anyone think of some good reasons to stay with UBB instead of switching to vB?