Part of the answer was a multispeed compressor. With two or more speeds, the system doesn't have to run full out on days when only mild cooling and dehumidification are needed. Full-speed use is still available for those really miserable days, but the compressor doesn't have to run wide open all the time. At low speed, the practical effect is that of a small compressor matched with an oversize condenser coil. The savings can be substantial, and most manufacturers offer multispeed compressors in their lineups.
Scroll compressors are so different that they practically defy description.
But their mechanical advantage is clear. Because they generate much less friction, they experience much less wear. The final product is a compressor that is very efficient and lasts longer. Any way you look at it, today's condenser units are better than those made just a few years ago. As a result of the Montreal Protocol, a conference that grew out of international concern over the ozone-depleting qualities of CFC chemicals, the EPA is mandating the gradual phaseout of Freon, or R22 refrigerant.