I've changed my old rating of 9 down to 7. I was aghast at season 3 and didn't finish. If you haven't seen the show yet, I recommend and hope you enjoy - season 1 especially, season 2 mostly. The Witch of Wickhadden is my favorite episode. Lovely additional cast members, neat setting.
I'm sorry for the folks who read the books first and were disappointed in the show! This series got me reading the books, which has been great. (Even those start going downhill. No disrespect and RIP, Ms Beaton.) I have no trouble reconciling 'book Agatha' and 'TV Agatha.'
The early formula was excellent, and I dearly wish the story/production team will try to recapture it. Shorter like they were, more of them, and less pratfalls and such. And yes, Katy Wix was a big part of that formula for me, too, I saw other reviews saying so! A real charmer, and her character plays off Agatha's so well.
For now, I will just rewatch the early episodes like I've done numerous times. It's a charming place to be.