Has Chevy Impala Handling Improved in 2006/07 Models?

I presently own a 2000 Impala and a 2003 Impala LS. I have been satisfied with both cars reliability, comfort and economy but, disappointed in the handling and ride at highway speeds. Seems at speeds of 65 mph or higher the cars feel unsteady and require constant steering corrections to maintain a straight path. The advertisements for the 2006 & 2007 Impala models claim improved suspension and handling. I was wondering if there are any drivers of the 2006 & 2007 Impala, who are also past drivers of older Impala that can verify or discredit that Chevy has finally corrected the unsteady highway speed handling issue. Thanks for taking the time to respond.