This, 100%. I am not as tall as 6'5", but I have spent a lot of time sleeping in a crew cab 3/4 ton because I was being cheap and lazy, and it was absolutely miserable. Best way solo is probably sleeping across the rear seats but this isn't practical when loaded up or with additional people.

My goto solution if it's in the budget for lazy comfort is some sort of imported double swag with the heavy duty floor and built in mattress. The main drawbacks are that it's pretty big when packed, you can't stand up inside it, and ideally you want to go through the hassle of importing a roll-top style giant drybag if you're going to throw it in the bed of a truck. I think I paid $150 USD for my waterproof bag, with $100 shipping from Australia. And, well, I guess they can be considered expensive also at $600 USD+

They're stout so they do pretty good in the cold, can zip most of the way up to screens for hot weather, are waterproof, and set up in a 2 minutes.