We travel with a 4 bike rack on the bumper which has been reinforced via welded supports as well as a tie-down on the rack itself. I don't like it as it is an absolute disaster trying to get the bikes on the rack positioned in the right manner so they all fit.
Friends of ours travel with a bike rack described here and love it Arvika - Home
It mounts on the tongue over the propane tanks. So this year, I bought the 2 bike model and will continue to use the rear mount for our other 2 bikes. Although the Arvika models are pricey, that comes with convenience and piece of mind.