I don't think essence users are very much powerfull than others, see that essence should be more powerfull because the armor/equipment limitations that other realms don't have. So it is not unbalanced to think that in magic essence must be a bit more powerfull.
But in this case, the 'powerfull' word means 'versatile', in other realms you have spells not less powerfull (detection, telekinesis and others are more powerfull in other realms), but essence cover more 'range' of situations. I think it only has not healing.
But don't forget that priests can be very powerfull as there are many priests spell lists in CC book, and many of them powerfull and usefull.
Also, the lists introduced in the EC IMHO are not incredibly powerful (except for the Magic Staff list, which is an exception...) so I think that there are no reasons to worry.
I don't see magic staff in that way, it has its limitations, and it has a negative factor (the -20 SCSM if no staff in hand) as balancing rule. Further, it depends on your character view, for example, I have a magician, but I DON'T USE MAGIC STAFF, I really don't like the image of the magic user wearing a robe, with the pointy hat and a staff (I really hate it
), so my magician don't use robe, don't use pointy hat and don't use staff, he wear clothes as any of us, for example, more yet, I developed some 'transcend armor' if I want to wear some leather clothes as a like-punk style
I don't know about others, but in RPGs I usually make the character I like, and that is the more important point to me. If we are worried about making the 'optimal' character, then ALL characters would be the same one!.
An example: look at this image
the magicians are in middle and right-bottom, I really don't want to use STAFF