I'm neutral on the ET800 Yamaha clone (yes, the original design was by Yamaha, back in the 1970s, an offshoot from their ET1200 one.) This model was designed when sensitive electronics were the last thing on engineers' minds, and they were wanting something that could power a pump, keep a light bulb on, or some other tasks in the field.
The good:
Cheap.
Fairly easy to maintain. Use the cup that comes with the gas cap, and don't drink either liquid being mixed.
Decent service life.
The bad:
Usually the included spark plug is bad and needs pulled straight off.
Needs a precise break-in regimen.
The carb is delicate and will plug up quickly unless fogged or run often.
It is not extremely loud, but it is noticeable. However, if you put it in a ventilated (but yet sound-resistant) box, the noise can be dampened quite a bit.
The ugly:
The power from this thing is dirty. Very dirty. There is little to no voltage regulation on this thing, the crankshaft pretty much gives what is coming through the wire. Add a load or drop a load, expect a spike up to 160 volts (as per various YouTube videos), until the governor action can get the speed back to normal.
This isn't a 1000 watt generator. Nor is it a 1200 watt model. It is an 800 watt generator and gets very unhappy when loaded past that.
What would I use this for? If I had a RV Chalet or a vacation house, I'd have one of these fogged and ready to go as a backup of a backup. However, just a couple C-notes more can get me a known, good, voltage-regulated Champion. A couple more, and I have a quality inverter generator from Champion that I know will give clean power. Generators are not really something I want to cheap out on. I'd rather spend a bit more and get something that I know will be able to do the job. Doesn't have to be a Honda or Yamaha, but at least a name brand like Champion.