Hello Hordolur, and welcome!
The first two or three books are a bit more weakly-written, and suffered a bit from some "early installment weirdness" (e.g. no more "Chauncy," and some elements of the Dresdenverse seem to work differently in the rest of the series).
But honestly, I find them ALL well worth reading; and by now, you're well past those stages.
Enjoy!