Nice review and you're dead on as to the laid back reasoning, That midrange dip is shared with the M3 (no surprise as the M40 is the M3 in a larger cabinet)it is also what causes the M3 to appear to have more bass then the larger M22, when in fact the M22 has the potential for more.

M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70