Arrogance isn't a big deal unless it's combined with foolishness (see George W. Bush for an example of this combination). Nothing I've seen on Hillary indicates to me that she has this combination of qualities.

For my part, I may not LIKE someone who's arrogant, but that's the last thing I give a shit about when I'm trying to figure out who I want as a president. I don't want a president who I could have a beer and shoot the shit with, I want a complete fucking genius who is superior to me in every conceivable way. That's because I'm voting for a leader, not a buddy.