Here are my personal thoughts: (Not trolling here or anything)

People with CONs complain because the cost of heals have gone up considerably. I will agree that this high MP cost in heals is a bit much BUT the class is still playable. As many mentioned, MP management is key now. Since the patch released, I've had to change my play-style to adjust to the new changes, and by now I'm able to manage my MP just fine by using the right skills. Using food to raise the MP pool also helps as well.

But the way I see it, this is an incomplete form of the battle system they have in mind. As it was stated in the "Battle Reform Blueprint":

The decision: attribute point allotment will no longer accompany gains in physical level, and will instead occur when characters rise in class rank. Although the amount in frequency of points awarded will be lower than previously, players will find that each point will have a more profound effect.
This alone puts a little relief, since if that goes in effect by 1.19, then those points I have put in MND will have a higher effect than now, which means a higher MP pool. I just hope they do it right so it offsets the high MP cost of cure spells and whatnot or at least a bit more balanced where you still have to manage MP but not to the point to where by 6 to 7 heals you're already almost down to 0 or very low MP.