As before, I didn't watch the debate live. Instead, I just read the transcripts here.
There didn't appear to be any knockout punches. It was pretty much more of the same.
One thing that I noticed is that Romney steered the conversation toward the economy as much as he could.
Another thing is that Obama claimed the military didn't want more spending, but that isn't a credible claim. Government agencies always want more spending.
As before, in the other debates, I think an opportunity was lost. Romney wan't all that aggressive. For example, how is Egypt better than four years ago? You see the peace agreement between Israel and Egypt unraveling-- how is this better than four years ago? Romney did point out that Iran is closer to a nuclear weapon, but what would he do about that? Now Egypt says they want a bomb too. How is this better than before?
I noticed in some analyses of the debate, that Obama got "snarky". Yes, it did appear to be true. But there was no "there you go again" moment to offset it. I don't know if this helps Obama, but it might hurt. If you are defending a weak record, it is no time to get arrogant. Obama is said to have an edge on foreign policy, but it was hard to see that from this debate. Yet Romney could not take advantage as well as he could have, in my opinion.
All in all, I'd say this didn't do much to move undecideds one way or the other.