There is not much difference. The difference is only about 15 sq. ft. inside and about 3 sq. ft. outside. If there is going to be two of you, I don't think it is worth even $10 or $20 (for three it might be).
Here is some info on both categories of cabins ...
Superior oceanview
D3 Located on deck(s): 6
Superior oceanview cabin with balcony
Square footage: 188 sq ft
Balcony square footage: 50 sq ft
Occupancy: Up to 2 guests (some sleep 3 or 4)
Amenities: Private balcony; sitting area, some with sofa beds; two twin beds that can convert to a queen-size bed; private bathroom with shower; vanity area; refrigerator; minibar; closed-circuit TV; radio; and telephone Cabin layout tipSee cabin layout
Deluxe view cabin with balcony
E1 Located on deck(s): 10 , 9 , 8 , 7 , 6
Deluxe oceanview cabin with balcony
Square footage: 173 sq ft
Balcony square footage: 47 sq ft
Occupancy: Up to 2 guests (some sleep 3 or 4)
Amenities: Private balcony; sitting area, some with sofa beds, two twin beds that can convert to a queen-size bed; private bathroom with shower; vanity area; refrigerator; closed-circuit TV; radio; and telephone Cabin layout tipSee cabin layout