To start with, I wish you well in doing your research. Hopefully, you will find out exactly how you want to live full-time in an RV over the next few years.
My advice comes with the caveat of not having anywhere near the experience as a lot of these folks, and I've never full-timed. But I do have 4 years of TT experience, and 3 years of pop-up experience before that. I am a fan of TTs, whether they be traditional trailers or 5th wheels. Motorhomes work for a lot of people, but I see two major disadvantages (at least to me). Others have mentioned the cost. It is much higher on MHs, I believe. The second disadvantage is mobility once reaching your destination. You would have to tow another vehicle behind your MH to get out and see things, so why not tow a trailer instead?
I also like having a tow vehicle to drive around for sight-seeing, visiting attractions, etc. It might be a 3/4 or 1 ton truck, but it still gets you around without disconnecting from your campsite. And it is always available for use when you get back to your home base, if you keep one.
I wish you well in your search. As others mentioned, getting something smaller and trying out camping before you retire is a good suggestion.
