GB difference Live vs Recovery = Why?

[bjm_]

I imagine if my disk is healthy.  I don't need to regualry create "Sector by Sector" images.  Correct me?
I'm now wondering (regardless of disk health) whether I should incorporate  "Sector by Sector" images in my backup routine. 

I've only restored from Live machine images. 
Will/May my restore experience feel different = WinPE vs Live image...Restore?

May I restore a "Sector by Sector" image generated in WinPE from Live machine?