No regrets here and I never met one current or past fulltimer who regretted trying it. Some find out its not the lifestyle for them, but thats a far cry from regretting they tried it. Today there are so many people trying it for a wide variety of reasons, I think its to be expected that many only do it short term and some stay with it long term. Not everyone who decides to try fulltime RV'ing intends it to be a permanent lifestyle change.
I did it for 4 years and loved almost every minute of it, but was ready to try something different after 4 years. I've also lived on a sailboat fulltime cruising the islands for 2 years, and before that traveled around the world as a backpacking vagabond for 2 yrs. Before that I lead mountain climbing expeditions and taught people to hang glide off the side of a mountain. variety is the spice of life, I couldn't do anything fulltime for more than a few years.