After having a 30' TT and 33' BH FW for the kids, I now have the TC for DW and myself. Kids and DW use to laugh when I pointed out TCs, but having camped in one growing up, knew the advantages. After a year of TC camping, my wife has fallen in love of the TC lifestyle - stopping anywhere, go down any road, turn around for the things we didn't see until we passed it - making the entire trip the journey, not just the destination. She even mentioned on the last trip, after a week of camping, she wanted a unit a little bigger with a shower she could actually use it.
The trick is to carry only what you need to and use the back seat for a few items. If you are the type that needs a lot of toys or just in case junk, you won't be able to make the TC work or you will end up with a trailer anyhow. '
Even if the small 815 I have, everything I need fits. I carry the leveling boards, grill, and chairs in the back seat. Everything else goes inside the camper in a closet or cabinet. I make sure that I have complete use of everything without moving anything. Nothing is in my when I stop, either for the lunch or the night.
But I am a very light packer yet have almost never needed anything not packed. Only exception was when I broke down once and needed to buy a $20 socket set for repair. Now there are times when it would have been somewhat nice to have something, but made do without it.