The main difference between a category 11 and the higher categories is the split bath in the higher categories. The size is 184 square feet vs. 214 sq. ft. , and as far as I can tell, the difference is in the bathroom. We've sailed in many different categories, and found them all to be very similar in size.
Compared to the cabins on other ships, they are huge. Reality is that you spend very little time in your cabin anyhow, but we've always had plenty of space. A couple hints...place the life jackets under the bed, which gives you more closet space. Suitcases can then go either under the bed or in the closet, freeing up floor space. Bring a shoe bag for the door for all the misc. bathroom items you need to stash somewhere.
I'm ready for the cruise...it's supposed to snow here tonight....