Even though I worked at Splash, I'll say that the drops on Tower are much, much scarier just for the simple fact that you don't know how many there will be for that particular time, you may shoot up really fast first instead of drop, and it's really, really dark at some points.
You know when the drops for Splash are. You can hear the rushing water and the screams (of fun!) from other Guests. Plus, you'll know when the Big One is coming because C-Lift takes a pretty long time to go up.
It's not that steep of a drop. It's a 45 degree angle. That means it's right in the middle from horizontal (0 degrees) and vertical (90 degrees). And it's over before you know it!