I really liked how they broke out the trigger and the mechanism and described and explained each part. Not once since I bought this book have my PCs merely "disarmed the trap." Now I link the trigger to a mechanism in some manner, and describe how they disable the trap by unhooking such and such linkage, etc.
In short, I found their treatment of traps in general to be better than the traps themselves. I am of the opinion that traps should be used sparingly and with logic, so I am nowhere near working thru this book. If I were, I would pick up the second without hesitation, as I found it to be a great help. But I only need so many traps...
PS