15k BTU AC on Parallel Hondas?

Has anyone ever been brave / crazy enough to try to get one to sync to something like another brand inverter genertor or source?

One person has reported successful paralleling of Honda and Kipor in the following two threads:
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/18202576/srt/pa/pging/1/page/1.cfm
http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/19588428/srt/pa/pging/1/page/2.cfm

There is a lot of misunderstanding out there about the Honda inverter generators. For instance, Honda says to use only Honda parallel cables, only 2 generators can be connected in parallel, and they must be identical models. There are multiple reports of all these requirements being violated with no ill effects, yet many who aren't aware of it will confidently state than bad things will happen if attempted. As recently as a couple of years ago, multiple posts said bad things would happen if an eu2000i output were bonded to the chassis ground. For instance, one post said "Okay, just got off phone with Honda tech support, located in Georgia. They confirm, you can not bond ground and neutral on this generator model.", and now it's widely accepted that there's no problem doing it. My point is that when asking about doing something nonstandard, be skeptical of predicted results from somebody who hasn't tried it.

My "best guess" is that a Honda inverter generator will sync with any source the conforms to its voltage and frequency specs. I doubt that the result would be acceptable because of the voltage differences. The Hondas stand alone with a no-load output voltage around 128, and when they're pulled down to 120 they're close to being overloaded. Most of the other inverter generators are in the 120 to 122 volt ballpark with no load. Because of this, the Honda would always be the primary power source, and no power would be drawn from the other source until the Honda was close to being overloaded.