Like Montanaro, I've never had any luggage lost or anything stolen from my luggage. A few late bags, but everthing always arrived eventually. I too have had good success with rolling duffles.
The few problems I've had with late bags have generally been when I've had to make connections, espcially when using more than one airline. Hence I fly direct whenever possible, or try to make connecting flights on the same airline.
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"Toto, I've a feeling we're not in Kansas any more."
-Dorothy, in The Wizard of Oz