That's what I wondered...is Blizzard Beach qualitatively better/more themed than the average waterpark (that costs much less!)?
The ski resort theme is cute, but to be honest it didn't really wow me the way disney theme parks do--it just felt like a cute little theme rather than feeling like I was transported to an actual ski village--after all, it was 90 degrees, there was lots of lush Florida greenery around (pretty, but not the pine trees you'd expect in the mountains) and you have all the blue plastic water slides and bright yellow tubes breaking the illusion. Not the same as, say, Asia in Animal Kingdom where everything looks more "real."
Dining is also more typical water/theme park fare than some the other disney parks. Burgers, hot dogs and a few other pretty basic QS things--no TS restaurants or really creative/themed QS (missed opportunity if you ask me--they could have done an alpine themed fondue place or something, but nope, just typical american theme park food).
And while the slides were fun, there was nothing that blew my mind as different from an ordinary water park. Lazy river, wave pool, body slides, tube slides, big family tube slide--all pretty standard. Your teens would probably enjoy Summit Plummet (my kids loved it) which is definitely a "thrill" slide, but a lot of the others are pretty tame.
It made for a nice break/change of pace as part of a week-long parks trip, but I wouldn't go there just for one day when there are so many better theme parks in the area, including universal.