You're missing the best use of this spell.. farming!
1 sec cast time is awesome, I'm working on smithing and need to farm large amounts of no drop items from owlbears and sonic wolves in ... hollowshade? Round up a train of about 20 mobs and blast 'em.. 90% of 'em will fall dead from one shot then just melee the few survivors. By the time you finish looting and get another train built up, the 2 mins is up and you can fire again.