I’ve only used this iGen4500 once and it ran my AC with no problems. It only ramped up during start-up and then quieted back down. This was at 4500’. We’ll see how it does at 9000’ in a couple of weeks. I’d give it 5 stars if not for the pathetic way you have to drain the oil.
Only reason I didn't give it a 5 star was because I had to call the help line to have the troubleshooting done over the phone before I could return it. Sure enough it was the automatic choke that had gotten disconnected during shipping so once I tore the sides off I could see the disconnected wires. Apparently this is a common problem with this unit since it's a tight fit inside. By adding 1-2" of wire for some slack seems like it would solve the problem. Otherwise I'm very pleased with the purchase
I bought this for a new travel trailer we purchased, it work awesome. It is a great size, and had more power the other brands it same size. the best thing about it though, is I didn't realize how handy it would be around my home. Usually I would bring the project to the power, now I bring the power to the project. very versatile.