Never had any Dorking females from them. Do have their Delaware, really like them, big birds, good layers of jumbo eggs, nice temperaments, friendly. They are somewhat broody, maybe once every year or two, but not annoyingly often, the two I let hatch eggs stuck and were good mothers.
I've mostly had light or Mediterranean breeds from them that don't set, but of the other breeds that I can think of their Ameraucana blacks and blues, and their Spangled Russion Orloffs are really broody, 2-3 times a year if you give them the chance, they are rather more broody than I like. The BLRW, Welsummers, and Marans are somewhat broody, maybe try once a year or so. They also have a mixed breed standard frizzle that are nice birds, also quite broody.