Which is the better theme park in terms of experience?

I'm going to be in Orlando at the end of June and I wanted to know between Seaworld and Universal Studios which is a better experience (cost is not a problem). I will only be able to spend one day at one of these parks so going to both is not possible.in addition we will more than likely be going to Island of Adventure at Universal Studios and not the other portion. So which in your opinion would be better to go to? Im leaning towards Seaworld because of research i did saying how many say service at IOA is spotty at best. Is this true?