For testing, an ideal situation would be a generator load bank. I've used them a lot over the years at work, but don't have access to one I could play with personal stuff on. The load banks I've used would let you select Resistive, reactive or combination loads where you could pretty much select any power factor you want.
In the end, it all comes down to how the things work for what you try and use them for. Myself, I've found my little CPE units to be very fussy when it comes to power factors, where they often don't seem to provide the output I expect, even though I've quite familiar with generators, and how different loads affect them. Power factor not withstanding, I've found altitude is my biggest problem. It's rare that I trip the overload for anything other than an overloaded engine that couldn't provide the power to keep the voltage up. For my experiences, I almost always dry camp, and to date the lowest altitude I've ever used my CPE at is approximately 3800 feet. Other than camping, I pretty much never have use for my generators.
In a couple months, I may be able to find the time to document some testing with two different CPE 2000i's. Input as to what sort of loads people would be interested in seeing used would be helpful as I can't exactly drag a load bank home.
