That's pretty good! I used to use a 5KW unit, which used about a half a gallon of gasoline per hour, but all I could hook up was my fridge, my sump pump, my freezer, the microwave, coffee maker, a couple of computers, and an electric frying pan.
We have a well, so that meant no water. And, of course, no heat in the winter, and no a/c in the summer (and it's been reaching the upper 90s each day around here).
Because I'm all-electric, and have heat pumps, even with the 20KW unit, I can only run one of the heat pumps. But now I have water! TV! A couple more gadgets in the kitchen. A room air conditioner specially dedicated to the computer room, and the entire computer room (including two means of Internet access). And, for safety's sake, my father's chair lifts (he moved in in November 2011).
But the sucker uses about a gallon and a half of propane per hour, and last time I needed a refill, it was about $4 per gallon.
OK, Your propane is really expensive!
I buy mine for about a dollar per gallon less, and the generator idles often cuz we are not running AC.