The biggest issue is going to be getting uniform spacing of seed.  Spacing of corn is even more critical than spacing of soybeans, and you see more guys going back to using planting units - as opposed to drills - in planting soybeans.  Reason:  better stands.  If guys are going back to planting units with soybeans, why would you want to try to plant corn with a drill? 

If you want silage tonnage with a drill, plant sorghum.