The previous owner of our house had one, when he bugged out, he took it with him, he was long gone before we ever looked at the house - otherwise I would've made an offer to KEEP it...however, the concrete pad for it along with the NG pipe is still there, so, that will help with installation should we ever decide to do a full house genny. There are a few in our neighborhood - story goes (from neighbors that have been there awhile) that the transformer to the neighbor was very unreliable and for several years there were major power interruptions - so, enter the whole house gennies...I will say that having NG to your house is a HUGE thing...also, we used the gas fireplace the whole time, as you can imagine.
I have two portable gennies and we used one of them to keep us operational.