I have it. I was expecting it to give my next spell a duration of 20.
But all it seems to do allow me to cast a duplicate.
What spells do you use this with?
One with a long recharge time?
A 15 energy spell, Arcane Echo followed by another 15 energy spell that is worth something, then you have to wait to recharge to 15 energy so that you can cast 'the Arcana Echo' version?