I'm guessing this is mostly a bug in the support library, but on my phone (Android 4.0.3), the loading indicators are glitchy. Sometimes, they don't even show up at all, other times they freeze instead of spin.
On a side note, I really liked the old bars, they looked pretty neat with the dark holo skin. But either way, it's sort of annoying to have no indication in the app that it is working on something.
