ProsWhite cast: First of all, there is no white cast in the sunscreen, so that's not an issue.
In fact, even though it's a sunscreen, it's really surprising that there's no white cast. There is a slight tone-up effect, but it's not a full-on white cast. So your face looks a bit brighter.
This alone is enough to wear to school.
Greasiness: There's practically no greasiness at all. Even the most greasy sunscreens that claim to be lightweight will slap you in the face when you apply them. But this one is almost watery when you put it on, and then it dries down (?) or gets absorbed (?) in about 30 seconds. So it absorbs the existing oil as well. It's a godsend for oily skin types, but it might be a bit challenging for normal to combination skin types. It's an absolute must-have in the summer though.
ConsIt can't be used outside of summer. Even I, with oily skin, used it in the summer and then briefly in the fall, but my face looked so pale and dry, like it was peeling, so I had to wash my face thoroughly. In the fall and winter, absolutely not. I'm practically an oil well, the oil is gushing out of my face and flowing onto the ground, so don't use it in the fall and winter.
TipIt also works great as a makeup base. The lightweight, non-greasy texture is wonderful. I have oily skin, so use it. If you don't like the greasiness of sunscreens, use this. Just use it, everyone.