I've considered buying one for a long time. I have a friend who has the automatic start etc . It senses the power lose and kicks right in. Smokey has one at his house too do to the need for the lift for the wheelchair bound guy upstairs.
Everytime I go look I get swamped with all the decisions and end up putting off the buy. One of these days!
I have the heat situation licked as I have a stove that runs off the pilot light thermo sensor voltage. That brings some peace of mind since for several years , all the heat sources would be lost if power failed. I think as time goes forwar the need to be self sufficient will increase.