I THINK 7.1 IS WORTH IT MORE AND MORE MOVIES ARE COMING OUT IN 7.1 AND THE SOUND IS INSANE. THE PS3 WORKS GREAT WITH 7.1 YOU JUST NEED THE 2.5 FIRMWARE UPDATE
http://www.dts.com/Corporate/Press_R...NT_SYSTEM.aspx
IF YOU GET A GOOD QUALITY AVR YOU CAN MATRIX THE 7.1 FROM THE 5.1 BUT DOLBY TRUE HD SOUNDS GREAT IN 5.1 I USE BOTH IF YOU CAN AFFORD IT GREAT IF NOT GET SOME GOOD SPEAKERS AND COMPONENTS INSTEAD JUST MAKE SURE YOUR AVR HAS 7.1 SO IN THE FUTURE YOU CAN ADD IT.