First, as noted in the answer to the question above about Financing, a THOW is classified as "personal property". Without exception, this means financing is more difficult, loan terms are much shorter and interest rates are higher.
But it's even more important to consider these other factors as well:
◾ A THOW is a trailer, no matter what kind of fancy name it's given. This makes finding a place to park a trailer difficult. Most subdivisions and municipalities have strict rules regarding this. Even if a suitable spot were located for parking the trailer, it can be uncertain as to how long that spot will be available or approved. Always worrying about where you are going to park your trailer is not most people's idea of living a simpler and easier life.
◾ Sure, there are more and more THOW parks popping up which provide a good spot to park a trailer. However, the monthly rent in these parks can range from a low of around $450 to a more typical monthly price of $650, or more. That's a huge monthly expense for a 25' wide parking spot.
◾ Who wants to have to register their house at the DMV? A THOW is taxed as a travel trailer and in most every state will require title, road registration, and state inspections.
◾ A THOW depreciates in value and its parts and components deteriorate. Just like a new car, the minute your THOW rolls off the lot it is instantly worth LESS than you paid for it. So, if down the road you decide you want to sell it, you can be 100% certain you will be selling it for much less than you paid for it.
Compare those considerations to the benefits of an Aframes home:
◾ A 7 Day Aframes home is conventional construction built on a PERMANENT FOUNDATION on LAND (Real estate). Financing for real estate opens up many options for you including conventional home financing, FHA, VA, Rural Development loans, and more. You'll have lower rates and longer terms.
◾ Finding the perfect piece of land to put your new Aframes home on gives you stability, peace of mind and puts you in control of your life, not some trailer park. Another thing some do is find a big enough piece of land to put multiple Aframes on. Live in one, rent the other(s) out as short term or long term rentals. It's a popular approach. Gardening, full on homesteading, chickens, the options are all yours when you find the piece of land that matches your interests.
◾ A home is taxed as real estate, which is tax deductable and may include Homestead Exemptions available in many states.
◾ Real estate historically appreciates in value. So, if down the road you decide you want to sell, you'll likely be in a position to make a nice profit. AND, as your primary residence, when you sell it the profits can be 100% tax free.
So, there really is no comparison. The conclusion is simple and straight forward.