I own a 100x5 watt Pioneer VSX-D509S($435 retail, paid way less). I am considering upgrading to a Denon 2802 or Yamaha RXV-1200. I have 4ohm towers upfront and the Pioneer has a hard time with them(has shut off before), so I was thinking of moving up a little. PLII is somethign I want, and DTSES is something I would want for future upgradeability. But my real question is, WILL I NOTICE A DIFFERENCE IN MY SYSTEM? And will it be a $700 difference?