Newt Gingrich, not surprisingly, got prickly when Romney said he and the Heritage Foundation were in favor of an "individual mandate" during the ObamaCare discussion. Gingrich accused Romney of lying, but after Romney explained what he meant, Gingrich had to admit Romney had been correct.
This was not Gingrich's best performance.
Ron Paul is like the dairy section at the Safeway. You know where to find the 2% and where to find the yoghurt. You can depend on Paul to stay on message and to make his case clearly and concisely whether you agree with him or not.
Michele Bachmann had her best appearance since the first debate. Her ideas might be screwy, but within the extremely narrow limits of her world-view she did a good job of presenting them.
Rick Santorum should be dropped from these debates because his only goal is to pick a fight with whomever is ahead of him in the polls which is everyone else on the stage. He has nothing positive to offer and depends solely on being the class scold as an attention-getting device.