Unfortunately, I doubt you'll find an accurate measurement for the power. Bear in mind that a difference of 10W is going to be inaudible, and most people listen at sound levels which need less than 20W/ch.
The major difference is in their room equalization software. Denon's Audyssey EQs the subwoofer. The level of MCACC that's in the 1021 provides only minimal subwoofer adjustments. On the other hand, MCACC is more tweekable.