Older thread but thought i'd put my 2 bits in : )
Short version: For my wife and i an RV because we wanted the option of placement in established resorts/parks that a "Tiny Home" would not be allowed when i did my research.
My wife and i were getting tired of the 3 bedroom farmhouse on the acre of land...
The nest was empty thanks to the US Air Force taking good care of our two adult kids...
I spent many a day on the tinyhouse blog and similar sites dreaming of downsizing...
Then my wife caught the fever.
I started asking around the area at some of the local rv resorts as to what was allowed as we did not want to own land or traditional home and wanted to let "Good Sam" do the yardwork ; )
So after two years of research we purchased a nice 2006 (in fall of 2011) DRV Mobile Suite.
This is a shot off the web of our same interior on our 38 footer:
It has all the conveniences of our last home except no yard to maintain and the _view_ can be changed anytime we choose.
It is certainly built better than our old turn-of-the-century farm house. Steel frame/chassis and 3.5" walls with dual pane windows, central air, heat, vac, LED lighting, washer/dryer, etc... Power expense during the WET! Oregon Coast winter was ~15 lbs propane and ~800 KW of electricity for the coldest months... summer months have run Zero propane and ~200 KW electricity. WE LOVE the cozy comfort of the tiny interior, though by "Tiny House" standards it is palatial at 38ft long and full wall slides of both sides making the interior space a measured 14' wide.
New our unit sold for ~127K... we bought it from the original dealer for ~35K in pristine condition as the retired couple who owned it wanted a motor-home in trade. I could not have built such a quality "Tiny House" for this amount with the beauty of traditional hickory wood, corian counters, tile floors, etc for the same amount of $$ and then felt it was at all safe to tow down the road at ~18K lbs!! ( < We pay a buck a mile to a local when needed to move it...but we currently are enjoying seeing the flag of the 6th hole on the golf green out our kitchen windows : )
So there's my long version of why an RV for my wife and i.