I'm unclear on why supercritical steam is important for electrical generation. Anybody happen to know?

Reading through http://en.wikipedia.org/wiki/Supercritical_steam_generator indicates that Benson boilers are more fuel efficient (and perhaps less prone to explosion), but reduction in amount of fossil fuels used to turn a turbine seems to be sort of a moot point here.

Would super critical steam generation mean a solar plant can produce more electricity? Or that a supercritical steam generating solar plant is cheaper to operate?