Currently have an Onkyo TX-SR605, 7.1 90watts per channel. My friend says I should upgrade to a higher watt Onkyo like the 805 or 807. I am using my receiver for blu ray with my Oppo BDP83 and Pioneer BDP-51fd. My current set up sounds good to me but my friend says the higher wattage would help to drive the speakers and bring out more overall audio enjoyment. I have 5 older Jensen tower speakers and a Sony subwoofer. Should I upgrade my receiver? Any suggestions appreciated. Thanks.