Just got off the phone booking 5108 on the Mars. As someone else said, cabin sizes are the same but balconies differ. So, total square footage for deck 4 - 883, deck 5 - 980, deck 6 - 850. She didn't give me deck 3. Will be our first aft cabin so looking forward to it!. Also, just from pictures it looks like deck 6 completely overhangs deck 5 aft cabins so I don't expect it to be an issue that anyone would be looking right down on us.