I currently own an RX-v420 65 wpc, 5.1 receiver. I am thinking of upgrading to the HTR 5790. My room doesn't lend itself to 7.1 processing. I would be using this receiver in 5.1 mode for the forseeable future. I have very efficient Klipsch speakers and don't know if the 45 wpc increase would be of any benefit to me. Would the improvements in processing and setup over the last 3 years make this upgrade worthwhile? I am willing to consider any model or brand in the $600 - $900 price range provided the benefit is worth the investment. Any advice on this subject would be greatly appreciated.