This is one of my favorite shows ever! I am an American who watches it through BritBox. It is usually very well written but as with any long running show there is an occasional clunker. I think they have a very talented cast and the set and costumes are first rate. Some of my favorites episodes are the ones featuring Murdochs inventions and historical figures and events. Since I'm partial to the character of George Crabtree I always enjoy it when he is featured. Which leads me to mention that I think they miscast the actress who plays his wife. Her acting is fine but they just don't mesh on screen.
In regards to the occasional clunker of an episode, the season 16 two parter of Julia being arrested for murder was a biggie. They had Effie representing her and it was essentially Murdochs investigation skills that freed her. I would have fired her for such ineptness. The story was unusually short on common sense and a credible and thorough investigation of a crime and and was left to rely on scenes that tried to invoke emotions. I focus on this because it's such a disappointment when the writing falls so short of an overall excellently written show. Despite my personal thoughts on these two episodes this show is definitely worth watching and I highly recommend it!