Paul Waldman at the Washington Post Plum Line sums it up nicely.
... what we haven’t learned is anything new that the committee has discovered about — now see if you can follow me here — Benghazi. That was, you may recall, the whole point of this exercise. So what has Gowdy’s committee found that all the previous investigations didn’t? Anything at all? What do we now know about what happened on that night that we didn’t know before?
The answer so far is: nothing. Now maybe if they take another 17 months and another few million dollars, they’ll finally blow the lid off the conspiracy. But if they’re trying to argue that the committee exists only to learn the whole story about Benghazi, then it has clearly been a failure. If the committee exists only to hurt Clinton, as Democrats have been saying all along and now even some Republicans admit, then it may be turn out to be a failure on that score as well.