I am about to upgrade my old Carver Pro Logic receiver to the Denon 3802. I also will probably get an SVS sub. I have a Bose Acoustimass 15 speaker system and want to upgrade it but cannot afford everything right now. 1) Will I really notice a difference with the Dobly Digital, Pro Logic II, DTS, etc? 2) Will I really notice a difference with the sub? 3) Should I buy rear surrounds to take advantage of the new receiver capabilities, or save this money to put toward savings for speakers to replace the Bose later? My wife also enjoys this kind of stuff, just not as much as me. If I spend the money and the difference is not much improved, she will be hard to convince in the future when I wish to make other upgrades. Please give me your thoughts!