I lived out of a camper on my truck for almost a year, and it was the best year of my life. If your chosen activities align with RV life great. If not, well, it will suck. I was chasing the seasons to go rock climbing and backpacking along the west coast, which aligned pretty well.
Issues:
1) In the city you have a target on your back. Unless you have a home base to safely dock at pre-planned, finding spots to legally stay outside of RV parks can be the pits. It has gotten worse in the years since my trip, so expect to be hassled by cops now and then if you are poaching spots to stop.
2) RV's are mobile, but not suited to daily driving. Once you've setup camp, getting back on the road for groceries or trips into town can suck.
3) RV's get smaller in the rain. Cabin fever is real about just a couple days of rain/cold/snow/etc.
4) Bigger RV's have fewer spots in campgrounds to stay at, and it feels like it is harder and harder to find open spaces in decent yet affordable campsites even with an RV. Spontaneity is becoming a lost cause.
5) Many national parks and such have 1-2 week stay limits these days. Having to move every week or two burns a lot of money in gas/miles that can negate expected savings.
