Received my propane conversion kit for my Honda EU2000i Generator last week. This past Saturday, I did the conversion, which took about 2 hours.
This conversion is not for the faint of heart. You take the covers off and remove the gas tank and all associated fuel lines to the carburator. You then remove the carb, remove the fuel bowl, then remove the high speed jet. Then, you (gulp!)

drill out the passage where the high speed jet was, to 15/64. After that is complete you clean the shavings out, and screw in the new propane jet, remount the carb, and do the rest of the propane plumbing, which includes the carb vapor regulator. Then put it back together and hook up the tank for testing. Mine fired right up after a few pulls.
Why did I do this conversion, you may ask? After using generator extensively through 2 hurricanes last year, I found refueling late at night in darkness, holding a flashlight in my teeth in 40 MPH ++ winds to be a real pain. Gasoline on hot mufflers is not good

I can now get over 4 gasoline tanks worth of running out of one 20 Lb bottle, or better yet, we are going to get a 100 lb cylinder for this year. In a pinch, we can pay the big $$ and get an exchange cylinder almost anywhere around here.
For camping, I feel it is easier and safer to haul a propane cylinder, or just use one on the Airstream, versus hauling a plastic 5 gallon jug of gasoline around.
Another good selling point on the propane fuel is no old gas sitting in the carb and fuel tank during the months the generator is not in use. Generator can be stored inside with no fuel fume or leakage worries, if disconnected from tank.
Cost of the kit was around $99 plus shipping and tank hose and regulator.