The books have changed since Changes. I don't know if quality is the word, but a style change. Earlier books seemed more slow paced, figuring out a puzzle. After Changes they seem more like an action movie. I prefer the earlier books.
I see why you would say that a style change has occurred, but I disagree. I think it's a scale change.
Up until Changes, we were dealing with Harry Dresden: the only professional wizard in the Chicago phone book. He solved cases, did jobs, made snarky comments, and caused a lot of property damage. Chase and action scenes were abundant, but on the scale you would expect from a mid-budget television show about an inner city superhero.
Post Changes, we have Harry Dresden: the reluctant Winter Knight. He solves unofficial cases, does jobs, makes snarky comments, and causes exponentially more property damage. The number of chase and action scenes is comparable, but each one has had its FX budget quintupled.
The only exception I can think of is Changes. That one feels like Dresden's version of the first Avengers movie.
What I suspect is happening that is causing some readers misgivings is that the scale change is removing the story from a relatable setting. We related to the PI and his clients more than the Winter Knight and his colleagues because they were more understandable. It's easy to imagine a guy down on his luck and living in a cheap apartment below Mrs. Spunklekrief, and very relatable. The same guy parkouring over crystallized monstrosities in an underground mega prison on an enchanted island is still a sympathetic character, but his circumstances distance him from us as an audience. Ditto situations, etc.
That being said, I like the in depth look we're finally getting at much of what was teased in the earlier books. The Fae were nebulous and above it all before. Now they're understandable characters. The Red Court war has run its course, and their absence isn't just another baddie put down. Their demise had world-changing consequences.
Matters of taste are not to be disputed. I, for one, am excited to see what comes next (no, not What Comes Next from Ghost Story. Hopefully I have many a year left...).
