Mainly it's the locations...Cat 11's are on decks 5,6 and 7...with the Cat 12's on deck 2 forward. They are both inside staterooms, with 184 sq ft... Oh...and cat 12's only sleep 3 people where cat 11's sleep 3-4 people.[/QUOTE
Are you sure that they only sleep three? I just booked two Category 12 rooms with the onboard special and booked four people in each. The big selling factor for this category is the chance of an upgrade. We booked Cat 12 for our 2/26 cruise and was upgraded to an 11 on deck 5. There were only two of us in one room and three in another... so... you have me curious now if the two rooms of 4 that we just booked for 2/06 are almost a definate upgrade (if 12's are only for 3).