The upstairs of B is such a messy layout, so it would have to be A for me. I don't get this obsession with en suites and dressing rooms atm, it's just more stuff to clean! An internal family bathroom would put me off too, esp if you have young DCs.
Would you use the dining room as a dining room? I think that's the crux of the 'too many doors' issue in dining room A. If it's going to be a playroom or den for teens, for example, that will work better than having to walk round a big dining table as they have it laid out.