To all vB to IPB switchers ... core features to you miss from vbulletin?

Yes, it does.

 

The most annoying thing I find about IPB compared to vB? Unsubscribing from topics (via email). Messy, messy, messy.

With vB, you can click a link and you're unsubscribed.
With IPB, you have to go to your profile, find the subscription, click it, then you're done.

Things I love about IPB compared to vB? Lots.
Template editing is just a snap, like it should be.
Permissions are just so much better handled
Facebook connection is there, and supposedly twitter is coming in 3.1. vB finally (years later) put something together in their core product, but too little too late.

I moved my free site support over to IPB a couple months back, and, despite the delay in setting it up (apparently the internet is supposed to close @ 5pm, why didn't anyone tell me? ), it's been running rather decent.