I would second many of the suggestions. Knowing that we definitely wanted to travel once we retired, we searched all alternatives, mostly used, from Class A diesel pushers down to a popup camper small enough to be pulled by a large motorcycle. We had a large popup camper, but no vehicle large enough to handle it, but we knew we liked the camping lifestyle. We liked the Class B concept, but we were concerned about the space issue, especially in light of their extremely high cost per square foot of space. We saw one parked at a used car dealer's lot, I wanted to look at it, but my wife refused to consider doing so, due to the space issue. So our search for the perfect vehicle continued for several months. Later, by happenstance, we drive past the same car lot, and the Class B van was still there. This time, my wife consented to look at it. I contacted the absent dealer, negotiated a price, and we decided to give it a try. We could not be happier with our decision! It is a 2002 Leisure Travel unit, built on a Dodge 1-ton chasses. As you can tell from some of my posts on this site, we have had some issues, but nothing super serious. However, one must be able and willing to troubleshoot and be willing to ask for advice. Remember that a motorhome is a combination of a house and a vehicle, both of which give problems at times.
The comment was made that you must get along well with your spouse. I whole heartedly agree with this. It is a very close environment in which very intimate situations exist. There is no personal space in the coach. Perhaps the situation is more extreme in our coach in which we have what I seen called a "transformer" bath where the shower, if used, is in the middle of the hall with curtains and a drain, plus the toilet is with the clothes closet and when used, the closet doors are opened and if more privacy is desired, slides are extended. BUT, we really like this arrangement and we wish it were more common in more modern coaches as it really gives us more space for other purposes. We would choose that arrangement again, but it is not for everyone.
A couple other considerations, not previously mentioned in the thread, is the bed orientation--is it length wise or crosswise? Ours is crosswise, being a potential sofa, but we leave the bed down all of the time, which is very convenient. We would hate to have to make up the bed everyday and have to have a space to store the bedding. But it does mean that the person on the outside has to crawl over the other person when needing to get up in the night. And the width might not be enough for a tall person. Length wise beds probably means you will have to have a longer coach to have space for other purposes. Longer coaches are not quite as convenient for parking.
One feature that my wife wishes for, would be an eyelevel refrigerator. Ours is under the counter and requires one to get on hands and knees to see what is in the back. But it is surprising how much it can hold. Most refrigerators are under the counter for Class Bs.
We are really glad we "took the gamble" on a Class B and love it for our current purposes, which is mainly traveling and sightseeing. We have not done any extensive camping in one spot. We do feel that if we started to do that, the allure of a Class B would diminish. However, with the relatively low cost of our used Class B, I envision the possibility of even keeping the Class B after purchasing a larger unit to have the best of both worlds. I've even imagined towing the Class B behind a Class A instead of another vehicle!!
Good luck with your search. Find something that you are comfortable with, financially speaking, and take the plunge. By purchasing used, you will have the freedom of learning your likes and dislikes and being able to someday trade for your ideal unit, if that truly exists, without suffering major depreciation loss.