Last summer, we did a split stay, first AKL for 5 days, and then the Contemporary for 2. My family LOVED both hotels. What a great choice, because they're both so different, you'll have completely different experiences.
My only tip would be to find out all that's going on and see if you want to participate. Also, make sure you call each morning for turn-down service for that night...it's totally free, and the CMs leave chocolates and African proverbs on cards on the beds. They arrange the pillows and turn down the covers, dim the lights and put on soft music, and put any stuffed animals they find in the room into cute positions. It's very welcoming. The pool at night is awesome, with the lighting. You really could feel like you were in Africa, if you let your imagination run free.
When we first walked into the Contemporary, we thought WOW, this place is cool!!! It has a more vibrant and exciting atmosphere than AKL. The gift shops there are the best on property, and even though I hardly bought anything, I went in everyday just to look at everything. Some people say the pool is dull, but it's shaped like Mickey's head, and it overlooks the lake. It's nothing super duper special, but remember it's Walt's baby, this hotel. At night, when it's all lit up, it's spectacular. The rooms are bigger here than at AKL, and you do feel the extra space. My tip/advice would be to try not to compare the two while you're there...see them for the two magically different places that they are.
Have a wonderful trip; I wish I were going!