The entire iron works right side will get you a whopping 8 more CP than the previous BiS. Caps on craftsmanship and control are a little higher, but it will take some really hardcore melding to make use of that. It's a lot of Gil for what seems to be very little stats.
My 170 accessories are already melded with max CP, 7 control, and 6 craftsmanship. If I had cheaped out more on those melds, I might be more inclined to do the new stuff.
I suppose we won't really know if these are needed until we see the new stat requirements. My strategy so far has been to try to max things as much as possible on the left side and spend the Gil on grade 5 for the guaranteed slots there where it has made sense.