Cassiopeia changes

As you may have noticed on the PBE server cassio's E has been changed. Now at 100 stacks it heals you only for 0.06 AP instead of 0.1 and when it kills a unit it gives you back the mana spent for the skill and 1.5% of your maximium mana instead of 3%. I think that the heal change is fine cause it was maybe a bit OP but let's see the mana regeneration change in details: by building a seraphic embrace (full stacks and 5 points on Q) just one E that kills a minion gives you back almost as much as the mana you spent on Q (71 mana back without mana on runes) but with the new one you need 2 minions to almost compensate the Q and 3 or more to gain mana but now to fill back up your mana pool will take double the time. I think that maybe 2.25% of your maximum mana per unit killed would be better but what do you think about both the changes?

(hope you understand what I wrote since I'm not english)