Yes they all vary, for instance you may find that it is geographically independant when you look at the results, in my area at the moment Indesit/ Hotpoint are booking 4/5 days ahead for trading and warranty calls, whirlpool the same, Serviceforce 3/4 days, within 48 hrs.
Again idependant service is the preferece of the customer as know one wants to be waiitng a week or more to get their appliances repaired.