My wife and I are considering downsizing from a 40' 5th wheel to a camper van 21'-24' long. Looking at Roadtrek and Airstreams right now. Difficulty with 5th wheel range from 2 blown tires and $9,000...
If really concerned, rent one. This is definitely an individual preference. Some people need more storage than others.
As a single male, I don't really need much, so a class "B" provides plenty of storage for me, especially with putting everything into clear plastic tubs to minimize wasted space in the oddball nooks and crannies.