In reply to Anna Fleming:
From an outsider who has dabbled a fair bit in both areas.
Yorkshire grit has tougher grades.
Yorkshire grit often has tougher conditions. (Further north?)
Yorkshire often has scarier looking or more intense looking roots. (I can't summon up the courage for Cow Udder or Bald Pate!)
Yorkshire grit is often more polished.
Staffordshire grit is the nicest, friendliest and bestist.