http://imgur.com/86aX404
It looks likes sages are unbalanced with their mirror class. There is a major concern with a class balancing issue. As you can see for sages you can only cast mind crush as 30 meters while sorcs can cast crushing darkness at 35 meters. Both of these toons are level 60, both of these toons have the same disciplines. The only thing that is different is their gear which is why the damage is different on the tool tips, before you ask there are no different set bonuses between my two toons.