It is features like this that make xenforo FEEL so interactive.
vBulletin can blatantly copy the LIKE feature of Xenforo but that's not going replicate the overall feel of xenforo.
For that they would have to migrate all their vB users to xenforo.
I am probably the only one who feels this way, but I find both the elements mentioned in the OP infuriating. The pop down notification serves only to block the navigation (I know it can be clicked to hide, but why should I have to?), and as for the loading indicator, I hate anything locked to the viewport for any purpose (feels oddly claustrophobic, hard to describe), least of which something that is animated.