I haven’t read any of the books myself but am a big fan of dark humor in the Edward Gorey-ish vein and so quite enjoyed this.
Very nice! I didn’t know the final book was coming out soon. And The Beatrice Letters? Awesome. 
The Beatrice Letters is on sale today!
Better than reading the books is listening to them read by Tim Curry. Reading them the repetitive and very twee style gets dull, but Curry’s voice transforms it into something quite fun.
My kids and I have followed the whole saga, but only on audiobooks. When the final book comes out, we will remain on tenterhooks until we can hear it from Mr. Curry.