Hard to beat "Spectacular".
I say just return everything and go back to the way it was before if the sound was better the way it was before.
Definitely don't spend money on something that doesn't sound as good as the old system.
How much did you pay for the Denon X2400?
You can get the Denon X3400 brand new for $599 from
@DigitalDawn. It has Audyssey XT32, which is a step up from the X2400.
Also, when on sale, the Denon X2300/2400 is usually $450 brand new on Amazon. The Denon X3300/3400 is usually $599 brand new when on sale on Amazon.
You can also bring the X2400 back to Best Buy and ask them to price match Amazon on the X2300 for $449. They may do that, instead of losing the sale altogether.
https://www.amazon.com/Denon-AVR-X2...F8&qid=1522435332&sr=8-1&keywords=Denon+X2300
Best Buy may also sell you the X4400 for $599 to price match the X3300 from Amazon.
https://www.amazon.com/Denon-AVR-X3...F8&qid=1522435459&sr=1-3&keywords=Denon+X3300