The Premium Sport Edition adds some cosmetics and features over the RX with Premium Pack, basically giving you the tech & safety pack as well.
I don't think there is anything an F Sport with T&S pack wouldn't have and obviously the F Sport has its own unique features such as the different styling, seats, instrument cluster, sports steering, sports dampers with active suspension, adaptive high beam, active sound control etc.
Info about the Sports Edition can be found here: