My wife and I have lived in our RV (36' Class A) off and on but mostly full time since 2005.
It has its ups and downs. Most importantly it takes a certain type of person and a certain type of couple. It's not right for everyone.
It was right for us for the last few years, especially with all the deployments, but now we're ready for a regular home.
Oh yeah, in case you're wondering, you can squirrel away a ton of cash in investments while living in an RV. The flipside is nothing loses value faster than a motorhome. If you get one, buy used and you better steal it, figuratively speaking that is.