Nothing much unique about truck campers that I have seen. I also have a 5th wheel in addition to our TC. Both have the same brand of furnaces, fridges, water pumps, converters (the 5th wheel's is larger), the same general propane setups and the list goes on. Most motorhomes or TTs are in the same situation until you get to the high end ones with hot water heat.
Recently I was having a problem with my water heater, an Attwood, not shutting off soon enough. I found the answer to my problem, not on the TC section of this forum, but in a comment made in one of the motorhome threads from someone that fixed the same problem with their Attwood.
Not having it's own running gear is about all I have noticed that would qualify the TC as being unique. We are on our 5th truck camper at the present time and normally will spend 90 to 100 nights a year on the road with it. While we have more "self appointed experts" than do most of the sections, we also have the best trip reports on the forum, in the TC section.