You might be surprised to know that power from inverter generators is usually very clean compared to conventional generators. Conventional generators can vary on frequency accuracy, and their waveforms can have lots of distortion. Inverter generators usually have purely sinusoidal outputs and aren't affected by variations of the engine speed so they are usually a rock solid 60 Hz (or 50 Hz).
As Brianl703 pointed out, most power supplies for consumer electronics are actually very tolerant of dirty power.
The inverter generator (Westinghouse IGen2500) was spot on-- it has a digital readout for load (in kWh), fuel remaining (sadly in metric), time left on fuel, engine hours, current runtime. It handled the fridge and two chest freezers switching on and off no problem, with my computer, router, modem, and the entertainment center in the living room running. I saw a max sustained load of 1000W at any time. Peak load I'm not sure of, I couldn't time all three fridge/freezers to come on simultaneously
nor did I try.
When I bought my Westinghouse 9500DF, someone on this forum recommended I buy a smaller unit for long duration outages-- and they were right. The smaller inverter generator runs on probably (just guessing) 1/10th less fuel.
Regarding power quality, had no issues with either unit. The conventional 9500DF would bog down for a half second when any large 240V motor driven appliances kicked on, specifically the 30A circuits I was running-- heat pump, hot water heater, clothes dryer; could only use one at a time of course. I'd see the lights in the house dim slightly for a split second, but all electronics on the 120V circuits coped fine with it. I had computer going, TV, lights, washing machine at some point, they were happy on whatever generator was hooked to it.
Like the above poster(s) mentioned, most modern electronics have a switching power supply that accepts 100-240+ volts and 50-60 hz and are plenty tolerant of power. No sense in creating two different power supplies for the world market, so they accept any voltage and frequency between the world norms. Beware of any electronics that have a switch to switch from 120V to 240V, those are the ones you have to be careful on, with crude generator power. These days that switch implies the cheapest / lowest cost technology the manufacturer could possibly use.