The hitch weight is over you rear axle not your bumper. With a bumper hitch you will squat your pickup more and take weight off your front end. You can turn and back a 5th wheel a lot tighter because you don't have to worry about hitting the back of your pickup, the 5th wheel basically gives you bigger angles to backup. Hitches for a 5th wheel are also heavier duty than a bumper hitch. The 5th wheel also makes the camper more stable for going down the road, it is just a better way to pull things. With the 5th hitches they have today you can pull everything out of your pickup in a few minutes and have a whole box to use for use.
Here is what I have in my pickups.
http://www.bwtrailerhitches.com/product/turnoverball
Here is what I have to pull my camper with, but there are other options out there, that pull out of the Turnover easily.
http://www.bwtrailerhitches.com/fifth-wheel