Far as I'm concerned, having been a car camper, used a pickup with tall camper shell, various vans (one with a permanent high top) and station wagons, and tons of ground tents over the years, the most fun and most comfortable and most efficient I've been is with my present setup of trailer, raise-able rack, and hardshell RTT. I can still use my van for sleeping when I want, too, like rest areas, truck stops, or when camping and I have guests who want to try the RTT.
I bought my Roofnest Eagle used. There's a ton of good used equipment and gear out there, much of it in excellent and almost new condition.
I suggest doing a lot of research on types, prices, and configurations or both trailers and RTTs, check out as many rigs in person as you can, and make a plan of sorts for how you want everything to work before you start investing in various components.
Here are some images of my set up over the last year, as one way to go:
