Ok, so based PURELY on resort, I have to say do not stay at Pop over AoA. Pop is an absolute zoo, the food court is so insane. We used to stay at Pop every single visit, not anymore. We ended up walking over to AoA to eat because we couldn't stand the crazy Pop food court any longer.
Also the rooms are so loud it's insane, the new flooring made it worse than it already was.
Now if you're talking for price, Pop will win because the Little Mermaid rooms never get any discounts.
Keep in mind with the sky liner opening both resorts will be even more popular.