I have the 2400is model.
Allow me to say it has been an extremely trouble free jenny and literally saved my bacon when we endured a 4 day power outage at our stick house. It powered 2 refrigerators and a freezer. But, it does need to be re-jetted if you run it at altitudes of 5000 ft.
I found this out the hard way when camped for a week in Rocky Mt NP at an altitude of about 7000 ft. By the 5th day the exhaust spark arrestor was so carbon fouled it would barely idle. I have since bought a variety of carb jet sizess and install the appropriate one dependent on the altitude it will be running at. Installation takes about 20 minutes and can be done with common tools.
Other than that, this model of generator has been bullet proof for me and powers the microwave and coffee maker simultaneously along with keeping the batteries charged up. It did power the 13.5 K AC on my previous RV (with no other power draws), but I have not had to use it to do so on my current 5W.
