Blue Goat,
I don't own either unit you mentioned, but I do have a Yamaha YG2800i. It puts out 2800 watts.
I absolutely love it. The inverter allows the engine to run at less than full RPM, producing less noise, when the generator does not require full power output.
I got it because I needed about 3000 watts to run the RV air conditioning. This Yamaha does it just fine.
I bought mine on-line from USA Light and Electric. They are at:
http://www.yamahagenerators.com
Great service and a good price. I needed parts (my fault) soon after I got the generator, and they got them to me in a hurry at a fair price.
My unit is relatively small. See their web site for size and weight. It fits on the A-frame of our travel trailer between the jack and the recessed LP gas bottles. I made a pigtail to plug the trailer's 30 amp cord directly into the 30 amp receptacle on the generator.
With this unit, I can also remove it and use it as a generator wherever I may need it. A permanent mount is nice for the trailer, but less versatile.
If you are buying one like mine, get the YG2800i, NOT the EF2800i. They are virtually identical, but the YG2800i has a GFI receptacle, and its a bit cheaper for some reason.
Loren