Wood or Aluminum Frame?

The big win on aluminum is lighter weight and no rot. Aluminum is no guarantee of quality. Poorly done or inadequate welds can be a problem.

If you do have a roof leak, you might get delamination but the bigger problem is the floor rotting since almost all RVs use 3/4 plywood flooring.

Most aluminum framed trailers have solid foam insulation. Wood framed usually have fiberglass bat insulation, which has been known to sag over time. I know the fiberglass bat insulation in my trailer was not installed very well. Some was actually missing in a couple places, what was there was quite thin. My trailer still manages to stay warm/cool as needed though.

I've had both now. 2 TT's with wood frame and, 1 TT & 1 5er with aluminum. I see no difference in "strength". It just .... if you want to hang stuff on the walls, wood studs are a bit easier getting a screw into than the aluminum ones.

Wood frames will usually have aluminum sided skin. Aluminum frames will usually have fiberglass skin. Both have very, very thin wood facade inside. Between the walls is fiberglass bat insulation for wood frames, like in your home. Aluminum frames have Styrofoam sheets for insulation. Both have their advantages and their disadvantages. It really is a 50/50 toss-up. Your choice. Find the floor plan you like, see if it's available by another manufacture with the opposite frame. Then compare the two in person. See which feels more comfortable to you.

Neither will survive a tornado hit, a flood, or a fire.

aluminum.

Having owned both I've found one has no advantges in being sturdier over the other. I would say its the mfg construction design... methods and materials that determines how sturdy any unit is.

I've seen more vehicle frame issues with a trailer mfg so called "lite" low cost units than their regular lines.
You want it cheap
You buy it cheap
So how cheap do you want it.

For kicks you might want to search this Forum for `wood or aluminum' and read the previous posts.
I like aluminum because it won't rot.

In pretty much every way the aluminum framed rig with pressure laminated walls are sturdier. Everything has a down side though. Pressure laminated fiberglass/aluminum construction has the dreaded de-lamination possibility that lurks about. Starts with a little leak somewhere and affects the under laid wood or fiberboard causing the fiberglass skin to separate. In reality the same thing happens from a leak perspective to wood framed/aluminum skinned rigs. It just doesn't show up with the skin bubbling up like the fiberglass does. You'll start to see it from the inside of the coach as it starts to rot away the wood. There are a few wood framed pressure laminated fiberglass skinned rigs like Nash from Northwoods. It is my personal opinion that a wood framed rig with slide is no where near as strong as an aluminum framed rig with a slide................and most person now-a-days want a slide.