We are on our third rig, and third Onan :) First was a bumper pull toyhauler with the 4000 gas. Next was a 5th wheel toyhauler with the 5500 gas. Now we have a regular 5th wheel and the 5500 LP. We didn't have the dealer install it, we got a referral from Cummins for an indepedent dealer. We haven't used it much yet but are going to give it some hours on an upcoming trip.
When doing our research, we did discover that they can be a bit more fuel sucking than the gasoline version. We bought two extra tanks (so 4 total) so we can easily swap them out, refill etc. But, the maintenance in general appears to be easier, and since we don't camp year round, it will be nice to not have to worry about draining the gas when we winterize.
I don't see any negative to one with 200 hours on it, and it's a nice thing to have already installed and ready to go if you ever need it. We are spoiled since we've never had a rig without one, but I like that we can literally camp anywhere and run anything we want in the camper without being limited (other than by the amount of propane I guess).
