I bought a 15 kw a few years back. Used it on a regular bassis to power my entire house and garage, some storms for 30 hours or more.
Pluses: Tractor always started to run it. Knew I didn't have to worry about a small engine not starting or gas for a generator.
Big enough to run everything.
Minuses: Sucked hooking the thing up. I always had something hooked to the tractor, so in a downpour/thunderstorm/sleet/snow etc... I had to go out, unhook the brushhog, blade, rake, scraper, spreader etc... etc.., fuel the tractor then hook it up. I had the gen sat on a platform so I could back right up to it. Still a PITA though.
The tractor wasn't always nearby. Often it would be in the hayfield or on a jobsite. Real pita then. Hook up the trailer and haul it home, take off the implement (see above).......
Loud. The gen makes a fair amount of noise. My nearest neighbor is 600' +- away, but still, on a hot humid night I prefered to leave it running so I could run the ac and get some sleep, otherwise I could hear other neighbors gens running further off:confused2:.
Have to be home to hook it up. I work 3 jobs, 2 with Fire Depts. If it's bad weather chaces are I'm responding somewhere. Left my wife to have to deal with it if I'm stuck at a call.
I finally had enough last year after over 4 outages in Aug totaling 36+- hours w/o power. Due to my sons special needs I opted to purchase a 6.8 kw auto start diesel Yanmar with auto switch. No more issues. 50 gallon fuel tank in the basement, burns 1 qt +- per hour and does everything we need to do.
Yanmar Powered 6,500 Watt Diesel Generator
The propane vs. is even cheaper, but the cost of propane is crazy compared to off road diesel. Glad I bought it, someday I will upgrade the gen set to a larger unit, but the switch and wiring is there to stay.
BTW, we installed the gen in Oct., that week the power co came through and did a major tree trimming in the entire area. Power outages went from several a month to 4 times in the last year now.
Good luck.