M Code is correct for the 5 channel assessment, according to the measurements of a
German magazine.
I downloaded the paid pdf versions of their tests and am posting here the results.
Basically the AVR-370 (same as 3700) measures 44W on 5 ch and 42W on 7 ch at 6 ohm.
The surprise is the AVR-270 which measures almost the same: 41W on 5 channels 8 ohm.
It is actually not a surprise for who, like me, owned both: I did not notice any power difference in switching from the 2700 to the 3700 and they sounded absolutely identical.