It is very interesting to look at various comparisons. I did not pick the AquaClass because you get a lot of special amenities that most cruise ships do not include, like iPod players, aromatherapy, etc.
MOst importantly you get full access to the Persian Garden thermal suite which is a very nice touch. But in reality, full access to that thermal suite normally only costs about $30 per person per day.
I am not sure Blu is actually that special as a restaurant. Anyone can dine there for a mere $5 service charge.
But you are correct, I personally do not think the AquaClass is worth the cost with a smaller cabin.