The 15k Guardian is the one I had. I loved it. I'd buy another in a heartbeat. It's a wonderful generator. It puts out 62.5 amps (A LOT!) and is no louder than an air conditioner. Comes on once a week for 12 minutes to stay ready to go when needed. The cabinet the generator is in comes with a lock to protect the generator. The cabinet is all 100% water and weatherproof. As long as you keep the air intake clear of obstruction and the exhaust clear as well...it'll run as long as you've got propane or natural gas.

Mind you the 15k model only runs at 15k when using Liquid Propane Gas. When running Natural Gas it'll only run 13,000 watts. Guardians out of the box are setup just to run Natural Gas and if you do choose to run off Propane...you will have to get a conversion kit. It's free. The kit basically is a different atomizer valve and 15,000 watt rated wiring.

If you do get a Guardian make sure you read the fine print in all aspects to make sure you're getting the wattage you want from Natural Gas.

But keep in mind there are Guardians that will run at more than 13,000 on Natural Gas. You just need to read closely.