For me, the ultimate RV would be a 40'+ diesel pusher with a Jeep as my toad. The upper class A vehicles are usually built like tanks and can easily handle a lot of weight, so the construction is done with heavier and better quality materials.
Most 5th wheel RVs make some or a lot of compromises to keep the weight down. Plus, you're then stuck at whatever destination driving around this monster 1-ton DRW truck.
Don't get me wrong - both are great RV rigs, I'm just partial to the big buses.
Now, the flip side is that a good Class A is the cost of a medium to large-sized house, but the biggest, baddest 5th wheel toy hauler probably barely touches $100k.