I've found that the wattage ratings on lights is just as unreliable as on heaters. You have to measure the load or you're shootin' in the dark in terms of evaluating performance. With the eu2000i in particular you know it's close to maxed out when the output voltage dips under 120. At 500 feet and 70 degrees mine stays above 120 volts up to about 1,800 VA. At higher elevations or temperatures, the 120 volt crossover happens at a lower load.
Will that 1.5 megawatt gen fit in the same space as my Onan Microquiet???