When I started, I was met in Denver by the CEO of Antarctica Support Associates. "How are you? How are things back in **? Thank you for coming back again. We appreciate your work and commitment to the program" He was warm, sincere, and meant what he said.
When RPSC took over, I was stopped at the door by an icy receptionist who said "Social Security Number". When given, I was allowed entrance. This after working on ice for 6 years at that point.
HR on ice became essentially a mouthpiece for RPSC policy, whereas ASA was more employee oriented.
ASA wasn't perfect, but from an employee perspective, it was much better. These are but a few of the differences, but there are many, many more.