FWIW, twin Honda 1000's can be used together in parallel using Honda hookup cables and the two of them together put out more continuous power (1800 watts) than a single Honda 2000 (1600 watts). So, two Honda 1000's might start and run a 13.5K air conditioner when a single Honda 2000 won't.
Also, each Honda 1000 is much lighter to handle than a single Honda 2000. Plus, two Honda 1000's provide twice the overall 120 volt source reliability of only one generator as a 120 volt source.