You and Tom have it right. The slides on the mountain structure will be very well themed. The others are at the level of Aquatica, which is significantly below anything at Disney. I'm sure all of the slides will be great, but I'm really only looking forward to the hydromagnetic slide and the lazy river myself. Of course, that Hydromagnetic slide is going to have an epic wait time and will sell out instantly on tapu-tapwhatever since it's only the single slide as opposed to the 3 flumes on Disney's master blaster (different technology, but close enough). It'll be cool to have a dark rideish slide in Orlando, I hope it's at least as good as the one in Colorado as far as theming.
The rest of the slides there are standard fare- off the shelf out of the Proslide catalog. People who think that Volcano Bay is going to overturn the water park industry know nothing about the water park industry. It'll be a fun park, it'll have 2 impressive slides and the rest will be stuff that you probably already rode at your local waterpark years ago. If you're looking for industry changing water parks/slides you'll need to head to the Middle East or Asia though.
Don't get me wrong. I have no doubt that Volcano Bay will be a smash hit. It looks like a fabulous park, though the location is horrid. In typical fashion, Universal is attempting to set the world ablaze with their "innovation" by repackaging stuff out of a catalog with a virtual queue system that's been in the industry for a decade and it's all being called a game changer... As if no parks already did this stuff eons ago. Still, it'll be a fun park aside from Universal bravado and ridiculous marketing.
Hey, at least there won't be any screens around the park. I'm not sure Universal is going to be able to pull off an attraction much less an entire park without projectors!
Come to think of it, I'm shocked that Universal hasn't just installed some motion platforms, used their tacky water splash effect that's on every one of their rides, and then placed a screen with a water slide projection and called the whole thing a "next gen waterslide". I better not give them ideas. I can see them running with something like that and calling it the worlds best waterslide at the world's only "water theme park".
I'll be touring the place in a bit and I can't wait to get measurements on that hydromagnetic slide. It appears to have a few drops that are much longer than your typical model of that type. Luckily it's nothing like Verruckt though, we don't need any of that mess here. The day I heard about Veruckt, well before it was built, I concluded that it would kill someone in short order- didn't take me long to be proven right.