It took me a while before finding the patience for that 26 but since I have Swiftcast couldn't imagine to play without.
Apart from almost trivializing a death (honestly, I hardly ever raised in battle without), it's useful for basically any skill with cast time. Even just throwing stoneskin at tank between pulls without need for him to stop. And an immediate aoe heal eh... It's basically an overclock skill. Ad helps you be more of a mobile healer (and this game needs aload of mobility) and less of a turret.
I have yet to get Eye for an eye instead, but I sure want it.