Custard creams are definitely less posh. DH insists on having custard creams, bourbons and jammy dodgers in the house. If they're crawfords he's happiest. I call these his 'common biscuits'.
Me, being posher than dh obviously, bought cadburys chocolate digestives the other day and DH could not believe they were cadburys and not mcvities. He thought me the epitomy of posh. Its a good job I didn't buy green and blacks eh ?!
For me custard creams are the most aspirational of the two, unless the rich tea biscuits are the chocolate covered ones. Neither are posh really, you need some hand baked cookies/cream filled macaroons or similar for posh. Belgian chocolate butter cookies....mmmmm yummy.
Nah - commoners make their shortbread with butter up here, wmmc - you can't move for the stuff, which makes it by definition common. But we also get shedloads of vension, and it's often cheaper than beef, so have maybe a different perspective on posh food...
well we had a complete disaster in the hat household last night. dh is still recovering from the awfulness of it all. he came home from Tesco's (and I reserve my right to have an apostrophe and an s on that) with PLAIN hob-nobs . he was devastated.
but there's a sliver lining - equally shocking - I have discovered that I prefer them . I don;t get it. I adore chocolate, but feel that plain hob nobs have a whole crumbly biscuity quality that the chocolate ones lack.