Class C Motorhome Reliabilty

While you are sorta comparing Apples and Oranges.....they are both Fruit:B
As mentioned, you'll have the same maintenance on either....just that with the "C", it's one unit, and with the TT & TV, it's two units.

Each has advantages over the other, depending on your needs. We liked the idea of the "C", since we didn't have anything that would tow a TT, and would have had to start off with a P'Up to go behind our mini-van. We got the "C" for about what it would have cost for a good TV....and a lot less than we would have spend for the combination of TT & TV.

If I had a job that allowed me to use a TV as a daily driver, it might have made sense, but I don't.

We also like the layout of our "C", having looked at many of them at RV shows. We like that the kids can watch TV in the back, while I'm driving, and that we can take our 8 dogs with us (that would be tight in a TV):)

I firmly believe that the reliability issue is really a product of how much maintenance you do on the vehicles...and that it won't matter which you decide to buy, as long as you get what YOU want, not what your friends and family say you should get.
Take their suggestions, but just like any suggestions you get on this forum, you need to take it, process it, and then decide what is best for YOU and your family.

Happy Camping:)

P.S.: There are plenty of 20-30 year old motorhomes out there, so they can't all be breaking down:)

Motorhomes probably break down "a lot" because people let them sit unattended for long periods of time. Many probably do very little to prepare them for winter storage. Then, in the spring, they get fire it up and head out for a couple thousand mile trip only to discover something's wrong.
Any large vehicle: truck, motorhome, etc. that is being asked to haul and/or tow lots of weight needs regular maintenance to perform at it's best.
The drivetrain in a class C is no different than the standard van or truck it's based on. Given proper maintenance it should last just as long.

LOL I am new to all this as well. We came from a TT to a C. There is certainly more maintenance with a C but no more than the truck that tows your TT.

As far as reliability of the house part it will be the same as your TT which is to say probably not very good! LOL! The Ford chassis will be about the same as any other Ford which is average to above average. My hope is the E450 will be above average reliability. The design hasn't changed much over the years. Ford has had plenty of time to get it right. I mean the front I-beam suspension has been around since before I was born!