Originally Posted by
Moirear
Surecast is more useful late into the game, IMHO. It does a great service when you know you're going to get hit by something that will interrupt your cast, which is especially critical in endgame scenarios on dps checks where you need to cast a spell with a long casting time or when cross-classing it to a healer job and knowing in advance you might get interrupted, but need to get a big (group) healing off.
Also, in case you don't know, at THM26 you get Swiftcast, which is Surecast on speed. This allows you to instantly cast the next spell you use, which is essentially even better than being able to cast non-instant spells on the move, and is generally one of the most awesome abilities to cross-class for the other Disciples of Magic.