We plant both - most often side-by-side. They both have their good points - and work well together, I don't like having to choose between either.
You can tell by the tracks here, this picture is from today- the deer are still pawing for soybeans on our property. Sure they are in the corn too - but Corn lacks protein - and soys are flushed with it. The deer will choose both when given the chance.
FH