Oasis vs carnival magic?

Okay so I'm goin on a cruise with just my grandparents so I need to go on a cruise that has a lot to do and a lot of Tweens I can make friends with. I love the oasis of the seas and i have Benny researching it for weeks. I looked at the carnival magic and it looks awesome to with the waterpark and ropes course. I'm a huge pool person so I would love the water slides and I love ropes course. I really like the oasis cuz it is so big and all the fun things to do. Which cruise would have more kids ages 11-13 and which is more of a tween kind of cruise!