Res
Selene/Eos
Succor (only on TT vs. fireballs)
Stoneskin (only if you are a WHM, otherwise Adlo is more effective)

Basically, whenever you *really* need to shave off about 0.5s - 1s from a cast time. I suggest not swiftcasting an Adlo due to the massive shield delay. If you are that close, you are likely going to miss the shield benefit anyway.