Some thoughts.
Who won? No one. Here's my ranking of candidates that likely improved their standings with casual voters:
1. Rubio: youthful, energetic, optimistic, and inspiring, good qualities in a leader. He got to tell his compelling backstory of coming from poverty and had a great one-liner about the Republicans having 17 great candidates and the Democrats "not one". Rubio likely had the most positive bump with voters.
2. Kasich: Made gains by virtue of the fact that most people know nothing about him. His record turning around Ohio is impressive, but he was evasive answering questions (almost all candidates were) and he kept redirecting his answers to his job as governor or even the work he did balancing the budget back in the 1990's, which hadn't been done for 30 years up till then (as we heard twice.)
3. Christie: One of the few candidates that answered questions directly, gave facts and statistics to support his statements, and directly took on Rand Paul (when he interrupted Christie.) Did not get flustered, in fact showed a little swagger.
4. Cruz: Took on most questions head on, had concise lists of things he would do, played the anti-Washington "I'm an outsider" card well (and often) and promised to tell the truth (perhaps too many times--you wonder about someone that has to come out and say they are truthful multiple times.)
5. Carson: Appeared calm and in control. Showed a sense of humor, handled questions well. Made a little error when he said something about the Air Force and planes from 1940 (Air Force was created after WWII.) Along with Kasich, probably the least known candidate, so he benefited from being on stage and having people get to know him a bit.
6. Huckabee: Had a couple of new ideas, at least to casual voters--that fetuses should be protected by the 5th and 14th amendment, and once again touted the consumption tax and noted it would hit prostitutes, pimps, drug dealers, and others that are evading taxes. Surely this idea must appeal to a lot of voters. He also had the best joke of the night in his closing statement. Still, some of his answers seemed like he was throwing red meat to his supporters.
7. Bush: The biggest thing he did was show he was not like his brother and father. That will help him with people that "don't want another Bush." He was competent and gave good answers, addressing the questions mostly head on. But he was uninspiring and was trying too hard to tell people he was a conservative. I think he used the term "conservative" or "we conservatives" or "I am a conservative" at least four times. There wasn't much fight in him either. When asked if he had called Trump a clown and a buffoon he denied it, though reports state that he said it. When Trump said that Mexican immigrants were rapists and criminals not a peep from Bush, and he's supposed to be the Republican's biggest friend to Hispanics, in fact, is married to a Mexican.
8. Walker: Biggest disappointment for me. Technically, made no errors but also seemed evasive, almost bored, and strangely didn't use his full time allotted. Competent but uninspiring.
9. Trump: Probably polarized voters more than they had been. Insulted Republicans by saying he wouldn't necessarily support the party nominee and wouldn't rule out a third party run. Also insulted women, Mexicans, and many others. His lame answer regarding "as a businessman I've only used bankruptcy laws four times" and "everybody else was doing it" was akin to a surgeon saying he's only killed four patients out of the hundreds he's worked on.
10. Paul: Came off as a confrontational ass. Immediately went after Trump. Then attacked Christie. Condescendingly lectured us about the constitution. Twice said he was a "different kind of Republican", whatever that means. Gave one of the weakest closing statements. He was a mess.