I would recommend that you check out the "Sprinter Source" forum. Go to the Leisure travel branch and you will find a bunch of Unity owners. Since it is a Class C, not a B, there aren't many owners here.
I would say that it depends on whether you want to hide the bed and have that wonderful big bathroom and a more spacious feeling up front. Or if you want the separate bedroom, so one can sleep when the other can be up front reading or watching TV or whatever. With the MB, it is always bedtime for both at the same time.