I remember Spike Milligan saying he once asked a lady who was working from an apartment where he lived in London, who are your best clients? She answered that would definitely be The English as they just want to get the deed over and done with and leave! Then he asked, who are your worst clients and she replied that would be The irish, because they want to kiss you as well!
BTW is there a difference between Southern clients and Northern Clients?
I suppose it would be like trying to distinguish those who are mean with money from those who are tight with money?