I have the Sony STR-DE635. It has 5.1 audio and 80 watts per channel. But, no DTS and no Prologic 2. I am looking to get the Pioneer VSX-D811. Which, not only has DTS & the prologic 2. It has 100 watts per channel, 6.1ES and 7.1 input. Will I notice a big difference and is it worth the upgrade? Besides, the fact it is DTS compatable. Thanks. ps-Anyone have any suggestions for speakers? Without spending a fortune.