Jessica,
Really, both water parks are fine. But for teens, I would recommend
Blizzard Beach. I think it has the more exciting, plummeting speed slides that teens seem to gravitate to (sorry for the pun!).
As to trying both, you could. But I don't know if you would end up thinking it was worth the time wasted traveling between the two. I think they are fairly interchangeable, so unless you are planning two separate water park visits (in which case, why not?), I would just go to Blizzard Beach and enjoy your time there.
The only reason why you might consider
Typhoon Lagoon over Blizzard Beach is if your kids might like the
Shark Reef. In this they can do some snorkeling through a reef that includes a few sharks!
If I can answer any follow-up questions, please feel free to ask me directly from my bio page!
Have a magical vacation!