I think the difference is about the same as a red apple and a yellow apple.
Each has their advantages and disadvantages over the other, and each is designed with a slightly different purpose. Both still accomplish the end result. Your stomach does not know if you ate a yellow apple or a red apple. Inside they both digest the same. In the end, you want a happy and safe camping experience with the least amount of "hassle."
There's give and take on both campers: Price, size, height, cost, storage. With your tow vehicle you have to decide what you use the bed of your truck for when not using it for camping, how much "stuff" you want to transport in it, if you want a shell over the bed or not, other "toys" you want to bring.
The best thing you can do is really make a list of what is really important to you, and then make a list a things you absolutely do not want for any reason. Once you get the list, I think you'll have about 99% of your own answer. Then its just a matter of going out and finding the camper that meets your criteria.
However, (I think) you already have your mind made up: Fifth Wheel. So, consider toy hauler too with the beds in the garage that raise and lower. They provide extra bed room space when you need it and open space when you don't. Just my suggestion.
EDIT: we chose the specific camper we have right now because we DO NOT want anyone camping with us, except the grandkids! No beds, no guests! Works for us! And the living room give us LOTS of space!
