We bought our Class B new in 2005 and for similar reasons as yours although this was our first RV. We wanted to see the country up close (we had been in a lot of it before) and seldom spend more than one or two nights in one spot in our travels.
We have now had it for 11 years and have 130,000+ miles on it. We never considered anything larger than a class B and have never had any regrets about our choice. We love the access it gives us to any road or parking (except parking decks), good mileage and good handling.
Ours does have a 3rd bed ability up front so we have occasionally traveled with grandchildren. We have done several trips of six weeks, but that has been about the longest.