Welcome to the search, I think you need to consider how the coach will be used the majority of the time, and go from there in your shopping. The more beds one adds to any coach, the less general living space one has. When looking at smaller coaches one thing many first time buyers fail to consider is the cargo carrying capacity, this can be a major limiting factor on how much stuff you can bring with you, particularly in the Sprinter B+ platform. I know some people don't like the term B+, but everyone knows what we are talking about described in 2 letters vs 15-20, so there it is. Some of these units with slides as delivered have under 600 pounds of cargo carrying capacity, this means all your stuff, passengers, pots, pans, clothes, camping chairs, bbq grill, etc. has to weigh under 600 pounds or else you are exceeding the GVWR of the chassis. (read up on CCC, NCC, and OCCC weight ratings, every few years for the last 20 years they have change dthe way cargo carrying capacity is calculated).
See this discussion on the 24MB https://sprinter-source.com/forum/showthread.php?t=33379