Plenty of skepticism ought to accompany you as you read this book. The stories are well written and may seduce you into believing his theories all too easily. Pack along some salt for a better taste. (If you are thinking of reading Think!: Why Crucial Decisions Can't Be Made in the Blink of an Eye, you might want to read my review of that one first.)
Especially important is to look into his explanation of how, why, and when the snap judgements worked in the cases he presents. He doesn't make the absurd claim that all snap judgements in all cases under all circumstances are better than thought out judgements. If you've carefully read Gladwell's Outliers: The Story of Success (which I've reviewed previously), you may notice that Gladwell's point in the narratives he shares are often subtle and sometimes easy to misinterpret. Maybe that's why it makes for such an enjoyable and engaging read!