Sorry this is so late, the outside world is rather hectic right now.
Romney's performance was adequate enough to establish that he's still the front runner. He neither gained nor lost ground, and that technically counts as a victory for him.
The debate organizers left out Johnson. He is a former two term governor, like Pawlenty. They included a former two term governor, a former two term senator, and a congresswoman who has just started her third term and hadn't even officially declared yet - she declared AT the debate. Gary Johnson’s inclusion would have provided a nice counterpoint to Ron Paul as happened in the previous debate, with one arguing theory and the other arguing practicality for the same points.
Gingrich did little to advance himself; he won't last long given that his whole staff just quit. He gave some muddled answers about whether he likes or dislikes the Ryan plan. He's the most hawkish candidate, but that's not a huge achievement since the GOP has mellowed just a little on wars.
Cain is starting to give disturbing answers. He really is in favor of having no Muslims on his cabinet unless he knows for sure they are loyal, but insisted he was misquoted on loyalty tests. Then he said he would restructure Social Security they way it was done in Chile. That's a position many libertarians will not appreciate, since free market libertarians are always given broad-brush blame for what monetarists (not libertarians) did there in cooperation with dictator Pinochet. If he continues that answer will come to haunt him..
Bachmann was a surprise. Given what is commonly said of her by political commentators, a viewer could be excused for expecting guttural grunts as her means of communication. Instead she not only used complete sentences, she seems smarter than Palin with whom she is commonly compared.
On gay rights issues there were two big questions.
First, would the candidate interfere if a state passed a law allowing gay marriage, would the candidate support a constitutional amendment against gay marriage. Some said they would interfere and would support such an amendment. Ron Paul of course said he wouldn't interfere and went even further and said get the government out of marriage.
Second, DADT is going away. Would the candidate overturn the repeal or would the candidate leave it as is. There were several who said they would overturn it. Ron Paul is good with DADT being gone. Two for two, he is better on gay rights than Obama, and that is certain to annoy a few progressives. Bachmann and Pawlenty both came out strongly anti-gay.
Most of the candidates, except Newt and Santorum, have mellowed on the war, making hat tips to Ron Paul on that that. There were also a few hat tips on economic matters such as the bailouts. He is very much the second place candidate against Romney.