I happen to think that these Congressional hearings -- whose purpose is to attack Hillary rather than get to the bottom of what happened at Benghazi and enact changes to improve things -- are a complete waste of time.
Very little of the Benghazi narrative will "stick" to Hillary, and the hearings are just giving here a platform to appear "presidential" with pre-prepared commentary.
The reality is that the email server issue is more likely to stick to Hillary -- expect she has already designated that one woman aide to be the fall person if the issue blows up.