Kirschental is west German show line but there are just a few here and there a few generations back in the pedigree so I would not call the dogs "Kirschental" line unless they are being bred by the Fullers or with their mentorship. Many WGSL will have Kirschental in the pedigree. My males dam was imported from Kirschental (Quellie vom Kirschental).
Herr Fuller herded with his dogs back in the day but usually his formula was to breed one of his herding females to a more "typey" West German show line stud. He certainly maintained working ability far better than many other large WGSL kennels but he has passed away and the dogs have been sold. Even before he passed the recently litters were pretty WGSL type. There are many lines that produce nice herding dogs such as some DDR and some other breeders of working line dogs. There aren't real strong herding lines since not many people actually DO herding. Many WGSL and WL dogs can do herding including the HGH style of tending large flocks.