We have had, TT, DP, Class C an on our 2nd 5th wheel, we love the room in our 40ft Kz G384FLT 5th wheel.
As a couple of OP's have stated if you have done any camping at all with a 5th wheel the more you back one in the easier it is. In fact backing a 5th wheel into a tight camp site is easier with a 5th wheel than a TT, you pivot point is over your truck axle not you bumper this 3ft to 4ft shorter depending on the bed of your truck. Also your swing in much more tighter, it's like a TT, it's knowing how to set up when pulling up to a camp site that makes it easier or harder...
As well DP are very expensive to maintain, your pickup take 10 to 12 quarts of oil, a Cummings or Detroit engine takes 30 to 40 quarts of oil, your filter on a pickup takes a quart maybe two, a DP takes about the same but the filter it's self cost three to four times more. Tires for your pickup may run a $250 per tire for good tires, a DP will run you $400 to $600 or more per tire depend on the band and size of the tire.
You can not take a Class C or a DP to just any repair shop where with a pickup most any good repair place can fix just about anything... Also like you stated you need a toad to haul behind your Class C or DP to go anywhere once your set up, with a 5th wheel you already set up and disconnected...
As well you can always find good used 5th wheels and trucks, you can read a number of posts on this site about people not ever buying new, it far cheaper and the last owners in most but not all case's have worked out the bugs. As there bad deals with either, sure, but if you look close and watch what your buying you can get some great deals on both trucks and the wheels.
We just traded in a 2006 Coachmen 5th for our new Kz 5th wheel, the old 5th wheel had a new roof only 3 years old, tires that were a year old, all the marker lights and inside light had been changed out to LED's, new axle bearings and seals (timkin)... The trailer was listed by the dealer and was sold in one week for 4k more than they gave us on trade which was 10k. Someone got a good deal on a 5th wheel that will last them another 10 years or more if they take care of it the way we did ...
Safe travels