I started with a similar setup on my prior vehicle (SUV). I really liked the Napier as long as the conditions were right (I wasn't 100% convinced it would keep water out in a proper rain, sealing is not as good as a self-contained tent, temperature benefits are gained by having an insulated vehicle...but typically not great to run the vehicle as you said). I (fairly quickly) swapped back to a ground tent, just so I didn't have to completely unload the SUV (some trips are easier than others) in order to sleep in it. I really did it as a learning experience, before I got into a proper build (as you said, things like RTTs are not insignificant investments) so I could learn what things were important for me to have for a fun experience.
So, I would ask you a few questions as "overlanding" is such a broadly interpreted term.
Do you plan on staying in the same place for more than one night at a time (regularly, obviously we all do things differently sometimes)? The less you plan on moving around, the less important a fast camp setup/tear down is, especially if you tend to do multi-day trips. IF you do move a lot, then that camp setup/tear down becomes even more important (this was one reason I quickly realized I wanted a clamshell RTT, they seem to be the easiest to setup/take down, and I didn't need more room than they offered).
What amenities are important to you? If you are happy with a cooler, that's a lot easier to take in/out of a rig than a fridge which typically is permanently mounted (I'm including a slide as permanent here). If you want a fridge, then that takes up room in the vehicle somewhere that could impact how you can use that space. I used a cooler/fridge as an illustration, but there are a lot of examples..water? heater? kitchen? etc.
How intensely do you plan on off-roading in this? Stock work? Great, just be aware of weight, might not be a problem if you don't add armor and such for off-roading, but the camping setup can add up quickly, especially if you take a couple people, pets, etc. (it all has to be accounted for!). If, you do think you have needs in the suspension area, I would suggest doing a little research to not do it too early and have to re-do parts of it (springs are probably the biggest issue here, but to say that's the only concern would be an oversimplification).
With those things said, don't overcomplicate it. You said you had a great time when you went out with it like it is, and that's really what all of this should be about (to me anyway). Making sure your rig works for your use case so you can get out and explore in the way that works for you and your family. So, you might have the perfect rig for your use case right now!