Length depends on the campground. At our seasonal site, I can easily make it to the sewer with only a 15ft section of RhinoFlex since the pedestal is in the center of the site. At the Goshen rally, I needed to add my 10ft extension to reach the sewer at the rear of the site. I also carry two 5ft sections of RhinoFlex.
I like the heavy construction of the RhinoFlex, even though it costs a bit more. The cheap hoses don't last very long, tend to flop off the stands, and are easily damaged.