I never have bothered to masterwork any armor. I didn't see the point.
I still feel like this got tightened down a little bit too much. I know they didn't want people to just spam upgrade themselves like water but I wouldn't mind a slight tilt back more in the direction that it was.
Many people aren't happy about the enhancement core requirement given how difficult it is to get them. It isn't difficult, but the amount of effort per core can be time consuming compared to other resources in the game.