I have some old GTI inverter with 1000W, simple technology , low price, under 100$. They had Efficiency at about 85%( Datasheet 85-87%). It was not high efficiency but ok old technology. I've tested this GTI2 2000W version. The efficiency of this new technology was indicated with pick efficiency of 92%. The results a have messured were not very impressive. I've tested it in the Battery Limit mode, so it easier to get more solid values as at Solar modules. I've tested this Inverter till 600W Output because of my Multi Meters. Here my results. Of course the difference of features between the Old GTI 1000W and this is impressive. The deliver was very fast.