I agree with mkaufmann!
I think the value for your money depends on what is important to you. Will you spend a lot of time in your room or will it just be a place to sleep, shower and change? Do you prefer the higher decks to the lower? Do you mind being forward or aft or would you prefer to be as midship as possible?
We DO spend a fair bit of time in our room and love to have the balcony. We don't care if we are one deck higher or not, so we usually book a Cat 6. And I prefer being aft to forward, it is just more convenient for meals, etc.
If my budget was tighter and I still wanted to have a "view", I would like a Category 9 over the 8 because the 8's are all forward (see reason above)

BUT I would be careful not to have a room under the Entertainment District if I could help it. Most of the quad occupancy Cat 9 rooms are forward and aft, so of course, I would head for the back.
With a teenage daughter, if I was just going to sleep in my room I would go for a Category 10 just for the split bath (and the secret porthole rooms of course). It is so convenient to have that second room to get ready in. If it was just my husband and I, the Cat 11 would be fine.
Hope I haven't confused you more, but as I tried to demonstrate, it depends on what your priorities are.
Cathy