The refreshed 2010 RDX is a significant improvement over the 2007 through 2009 in the following ways: 1) The ride is more compliant (suspension improvement) 2) The ride is quieter (the reduction in road noise was immediately noticeable) 3) The turbo is quieter from inside the RDX as well as engine noise which is more muted than before. I think they even changed some of the materials a little bit to quiet things down 4) The leather is improved (softer, more supple) 5) The navigation screen is a bit larger 6) USB interface has been added 7) The front grill on this one actually looks classy and more luxurious than the previous front end. 8) Etc, etc, etc.
Sports sedan like hand handling (reminds me of the 2007 TL), quiet interior and full of Tech.
Better gas mileage, hard drive based navigation and possible a 6-speed transmission (for fuel economy reasons) - but the 5 speed transmission is excellent.