Not full timing yet, But I think you will find those that found they disliked it after a short time are those that jumped in without testing the waters first.
You see lots of post here and other RV's sites of folks with little RVing experience selling their (Big) S&B and getting a Big RV, to live the dream. :S
They find the change too drastic, they are way too use to having lots of space and room for stuff. I think you find a much higher percentage of these folks bag it within a year.
Those you have been RVing either a lot in later life or all their lives, they are use to smaller living space and living lighter.
DW and I are working towards this, just spent 4 months working as host, and our existing full time jobs.
We found out two things for sure.
1# Envy of true full timers, (without full time jobs) life seemed better more relaxed and happier.
2# We both felt more relaxed coming home to the 5er, than we did when returning to the S&B after work.
One needs a RV that has what they need to live comfortably without excess. I think the highest "Failure Rate" would be those that try to go straight from a 2,000+ sq. ft. S&B to even a large RV. Too much too soon.
Just an FYI, the four months went by way too fast, we enjoyed almost every minute, we both grumbled about the two jobs thing from time to time.