I feel the leaked photos do a better job of showing the layout right now if your like me and can't log in to explore the ship.
If your having a tough time comparing it to the free lancer I feel there's pro's and con's to carrying cargo on the exterior.
With the Raft you can unload faster but if your attacked by pirates the cargo may become a "loot piñata" loosing cargo with damage.
With the Freelancer the cargo is more protected from pirates, will eventually take longer to unload, but possibly susceptible to interior fires?
I think if I were cargo hauling I'd prefer the stronger armor of the Raft over stronger guns of the Freelancer, but I'm sure others subscribe to the mantra "The best defense is a good offence".