lol vbulletin sucks, IPB is much more powerful in every way, especially with user-created mods.
But please, OP, tell me what critical bugs you encounter that mandate the upgrade of IPB?
Actually to be fair, that's one area in which vB has always been way better in, mods. It's only recently (since 2.2 or something) that IPB has introduced components (that work properly, not like early 2.0 or whatever) that many mods are becoming easier to install.
With vB mods, you rarely have to edit php files or anything, everything just works off the 'hooks' system. Basically like a plugin for wordpress (or any blog) which some of you may be familiar with.
Thankfully, IPB is getting better now, and I hope that minor mods also change to it because it really is a pain in the arse editing php files because everytime the software is upgraded you have to go through and do all the edits again.
But yeah, this a minor path denoted by the 3rd number, so it's not important for us to upgrade. Once 3.0 is out however that will be a different matter because that is a huge new release and we'll have to test that out first.