I find McGuires is most recommended and use it.. But frankly have had good results with Turtle Wax as well..
Most all Automotive wax products use the same wax. Even "hot wax" at the local quarter car wash is the same wax.. What varies is the carrier (That is the stuff that evaporates as it dries) and the concentration of the wax and a few other things.
If I really wanted to do a first class job...Simonize is still the standard by which they measure them... Of course the full treatment
Wash and dry, Use Pre-wax cleaner (Which applies like the wax and has to be removed with dry cloths) then wax and polish.. IS way more work than I ever feel up to any time soon.. Have done it but once and that was on a car.
Suggestion: IF you have not waxed the RV in a while (or yet) get some MPG logs and record MPG before and after.. I did.. (On the car too) and .. Saw a great light as it were.
I now wash and wax at least 2x a year before my great spring/fall migrations.