I discovered Downton Abbey via the New Yorker's Emily Nussbaum complaining about Laura Linney's 10-second talking head.
It seems to be a sort of counterpart to the late, lamented Larkrise to Candleford. In fact one of the leading actors of Larkrise, Brendan Coyle who played the main character's stone mason dad left that show to be one of the leading actors on Downton - according to Wiki the part, as a Downton Abbey valet, was written just for Coyle. I haven't seen any other Larkrise actors on Downton, but it's just a matter of time. One of the amusements of watching British shows is playing "where have I seen them before." So far I've noted that Jim Carter, the head butler at Downton, was Juliet's nurse - in drag - in "Shakespeare in Love" and the cute Scottish doctor, played by David Robb, played Laertes to Derek Jacobi's Hamlet in 1980.
Downton is a good show, although I do prefer Larkrise, mainly because I loved the postmistress character, Dorcas Lane, played to perfection by Julia Sawalha, currently reprising her role as Saffy Monsoon on Absolutely Fabulous.
David Robb as Laertes