Sorry, but "insulting to a question being asked for help and insight."?
Unless you were referring to the "Since you are apparently unable to read some charts let's spell it out for you:" that was actually addressing
bjorn who doesn't even understand that at the level of a 650W vs a 750W PSU, the efficiency curves (i.e. efficiency at different level of load) dictate that PSU on the same platform performs very similarly to one another.
You can actually go to any reputable PSU reviewer, (Aris here on Toms or
jonnnyguru, etc) and see that for yourself if the charts on how efficient the different EVGA B3s is still don't convince you.
His "Meaning it will convert a higher percent of the electricity it draws to waste heat at 20% than at 50%." is meaningless in this context. Here, even if I were to use his Wikipedia chart to do the math:
650W at 20% load (~130W) for 87% efficiency (149W drawn, ~19W waste):
750W at 20% load (~150W) for 87% efficiency (172W drawn, ~22W waste).
How big a difference does that 3 extra wasted watts make when a 400W system idling/web browsing at ~100-ish watts? Nothing.
650W at 50% load (~325W) for 90% efficiency (~361W drawn, ~36W waste)
750W at 50% load (~375W) for 90% efficiency (~416W drawn, ~41W waste)
So for your information, that's a total of 5 wasted watts compare to the 3 wasted watts at lower load between the two PSU.
It is when the system is under load that the actual amount of total wasted energy actually got significant enough, and even then for a 650W that is guaranteed to have lower efficiency past 50% of its rated capacity compares to a 750W from the same platform, the "extra wasted energy" is still far too low to actually matter, but the increase in either quality/capacity/quantity of its internal components to support the higher wattage rating will translate to less stress on the individual components (and therefore its temperatures) will matter (proven by the chart of fan noise/RPM which indicate the level of which engineers determine when components get hot enough to ramp up the fan to guarantee its safe operation, and so that they won't have to deal with a failed unit when its internals got/stayed too hot).
Even if you use some crazy number: 80% efficiency at 50W load? 62.5W drawn, 12.5W wasted. You just can't go low enough on low load efficiency to make a PSU waste so much more power at low load than it does at mid/heavy load (a good 80+ Gold will still maintain 70-75% efficiency at standby load, 2-15W load, 3-20W drawn).
So unless you think a PSU operates by the % rather than hard number of watts, volts, Celsius, etc; there just isn't evidence to support the go low on the wattage for max efficiency = best (it's just usually cheaper to go with enough wattage + headroom as needed/wanted and therefore why it's the general recommendation).