Linked Smart Objects in Photoshop Means Smaller File Size
There are many advantages of linked smart objects in Photoshop and I have discussed that in Linked Smart Objects in Photoshop CC 14.2. One more big advantage is and file size. In particular, files with linked smart objects have a much smaller file size. It is logical but not that easy to discover this advantage since Photoshop will show you in the Status Bar that file with linked smart objects has bigger file size for layered document?
I am not sure why is that, but just do not pay attention to Status Bar and what is shown to you as file size for layered document because when saved, exact same documents, it is obvious that file with linked smart object layers has much smaller file size.