Finally made it into this place with a friend in late january... and it is incredible! way biger than it looks. The main portion of the factory is pretty much hollowed out, but in good shape, there's NO vandalism, there's a ton of really cool equipment in the place (all crammed into the southwest corner of the building... watch for trip wires in there. I doubt that's their actual purpose but they certainly work well!)
One of the neatest features about this building is the office areas are "suspended" above the warehouse and factory areas. use your flashlights & cameras with flashes carefully, the entire building is pretty much surrounded by windows, and getting in is tricky due to the 75 foot treck across open parking lot in downtown belleville. We had several cops cruise by while we were in the place, and most of them slowed down a fair bit to scope out the grounds.
All in all, highly recommended, just kind of tricky to get into!