You're right! I just checked it. I have the Master Replicas Phase II helmet and it looks almost identical in the way it's made to the EFX Phase I helmet. It's been so long since I ordered it that I was thinking both were from Master Replicas. This explains why the Master Replicas paint has a more off-white color to it.
UPDATE: I just read that both were essentially made by the same team, so that explains why they are so close.
Yeah. If I remember Brian snagged a lot of Master Replicas people/stuff. They only offered the Phase 1 Clonetrooper and Red Captain. Too bad. Yellow guy and pilot would have been cool.