new ultramarine primaris shoulder pad set

[Yentzer]

So I saw the new Ultramarine primaris upgrade set on the games workshop webpage (the one with all the shoulder pads) and was wondering if they could be worth getting as they look more normal than the forgeworld ones and less ornate than the other ultramarine upgrade set. However since i don't have any primaris marines i was wondering if the scale might be off for regular marines?

[Stickeh]

The heads and shoulder pads are supposed to be freely swappable between the MkX and previous sets. The gravis pads probably won't be usable though.

[Prot]

I can tell you that I've been using my old um shoulder pad kit from GW and they fit very well on Primaris if that's any indication.

[Stoic Raptor]

I've heard that Gravis shoulders are the same size as Terminator shoulders and from what I could see while assembling my Aggressors, I'm inclined to agree.