Richard, welcome. You should be well-pleased with the M60s. As to the receiver, your "lean" is right: there's no good reason to assume that your 5840 wouldn't be fully satisfactory(as to power capability)with your M60s. Little weight should be given to what is "heard" from enthusiastic receiver owners. Keep in mind that power works on a logarithmic, rather than linear, basis; this means that even if the maximum rated power capacity was doubled(e.g. from 85 to 170 watts), the only result would be an ability to play brief peaks 3dB louder, e.g., 108dB rather than 105dB.
