I don't know specifically about the MBS program but I do know about the Piscataway campus.
I haven't been to the Newark campus only driven by, it's not so much a campus as Rutgers buildings in the city, Newark isn't known for generally speaking being the safest and nicest neighborhood (although there are areas that they are trying to build up). Generally speaking when comparing the two campuses the Piscataway campus is definitely a bit more prestigous you can see that just by the stats on accepted students between the campuses there is actually a notable difference. Newark is definitely a much smaller campus which can be a pro and a con because in Piscataway you are a goldfish in the ocean. There are many difficulties that come along with being on a bigger campus but overall in my opinion in this case it is much better. You have more options for classes, more resources, the campus is 100 times nicer, and overall I think that it is a better option between the two. As I said I do not know specifics about the programs in one over the other but I think if you have a choice go for Piscataway.