Looking at the comparison between the TC and small Class C (24 ft and under):
TC - fitting 4 people while driving will need a quad cab which puts more space in the cab area that isn't used during the camping
C - the space to fit 4 while driving will be usable space while camping
TC - if you need 4x4, this is your best; a C won't be comparable
TC - you can leave the TC set up at camp and take the truck out for runs, etc. If you want to go to town and the others want to stay at camp, they will have their gear
C - you can easily take the C out for runs and leave the minimal stuff at the campsite. If you want to go to town and the others want to stay at camp, you will have their gear
TC - may be able to tow a boat also (dependent upon truck size, TC size, boat size, etc.)
C - may be able to tow a boat also (dependent upon C size, boat size, etc.)
In your case, a TC may be the better choice. You can do more off-roading (boondocking), can drive into town while family stays behind with camper and gear. As for fitting a family of 4 - we did it when I was a kid with a family of 5 and 2-4 dogs at any given time (at least 1/2 of which were large dogs). We never had an issue with space. But in those days, space wasn't as big of a concern as it is nowadays - we shared because that's what you did.
