Power 'ratings' are very suspect, and easily manipulated. The frequency bandwidth, load, etc all can influence the numbers dramatically. Driving an amp with a continuous signal is not a real-world test. Far more important is current capacity and headroom. Even at very loud volumes, with speakers of typical efficiency, a very low wattage is needed. The loud peaks in a soundtrack are where the most power is needed, and those are almost ALWAYS very transient.

This is where headroom, and deep current capacity become more important than a continuous load reading. All else equal, an amp with say 60 watts continuous, but peak headroom to provide transient peaks to 120 watts will perform better in the real world than one with 80 watts continuous, but clips on peaks above 100 watts.

Also, don't forget how much of a power increase is required for only a minor increase in actual volume. 3 dB needs DOUBLE the power. Double the perceived volume is about 10dB, which needs roughly 10 TIMES the amp power to achieve.

In short, don't get too caught up in comparing this 140 wpc rcvr versus this one at 120 wpc. Other features will be far more important. Also, separates tend to have far more headroom capacity, so comparing a 60 wpc separate amp vs a 120 wpc rcvr isn't necessarily valid.