I was on the Elation last summer with my 15, 13, 11 and 7 year old sons- 5 in a cabin (and I am MOM). We had a BLAST! There was plenty of room. We had more laughs in that cabin than we have ever had in their lives. Is it tight? Yes. But there is PLENTY of room for clothes and personal items. The bathroom was just fine. We used two sets of bunks and a small rollaway (actually, my 11 year old slept on that more than my 7 year old). When we first boarded the room was erroneously set up with the king sized bed, two upper bunks, and the rollaway. It was VERY tight like that. After they switched it to the two sets of bunks it was fine. You might want to just set it up like that.
I strongly encourage you to put the whole family in one cabin. People will say that I am nuts but when I think back to me reading the Capers while the kids watched cartoons, all of us in one nest, I know that we would never have bonded the way we did if we had had two rooms. There was some insanity- the temptation is there to try to jump from top bunk to top bunk, hahaha- but that's part of the fun!
Here is my review- might help- http://www.cruisereviews.com/Carniva.../Elation79.htm