I read this aloud to my 8 year old son. He asked me to read the next one in the series, and I probably will, but I am curious if he'll pick up the rest of them himself someday. He did not seem enchanted. Like me, maybe he senses that there are better books in the series, or that each book builds on the author's vision and that the story will really come alive as you go. There is enough good here to suggest that's possible, including the fact that I've known many children who have read all thirteen books.
As far as stars go, I think this book falls between three and four. As other reviewers have noted, this one lacks rich, deeply satisfying characterization, but I suspect the Baudelaire orphans may gain more depth and individuality as the series progresses. (To be fair, chapter books at this level may often lack the word count for deep characterization, depending on the genre I suppose.)
In this volume, I was impressed that the situations were not sugarcoated and that the author's portrayal of the characters dealing with them was straight-faced, though there is lots of humor mixed in. What was left implicit was sometimes very scary. Maybe some children sense that without inferring much else. That alone might merit the fourth star.
I also appreciated the author's intent and attitude, the emphasis on the macabre, not in the sense of horror but in the sense that things may go wrong, despite it all. I really did not mind that the adults, even those who meant well, failed the Baudelaire orphans. (The letter of the law really isn't always just or satisfying!)
And finally: I was pleasantly surprised that the book is not action-packed. Events do not whiz by at a dizzying speed. I had to get used to that at first because it was unexpected and is perhaps uncharacteristic of contemporary, popular writing for this age group. There are surprises, but the plot unfolds slowly, logically. What shows is that the author wants to stand out from the pack by writing with style, with voice. It succeeds well enough to read on, that's for sure.