All A/C equipment that is currently being sold is computerized, but the most efficient ones come with the "INVERTER" system, yes they are efficient, "BUT" very sensitive to overloads, or low voltages, as well as humidity etc. etc.. they can be cheaper because with the same technology they make them more efficient "in quotes" but the component parts of the mechanical systems are making them more delicate and sensitive (MORE COMMERCIAL), they last less and therefore you pay more for defects and equipment life times