Pretty much every flight I've flown the last years have been paid with my Diners-card, = extra insurance in case of delayed luggage. My luggage has NEVER been delayed, although I have sometimes hoped it would be.
However, one travelagent I needed to buy a trip from didn't accept DC and so I had to pay with cash. Wouldn't you know it, the luggage was delayed five days on the outbound and I am still waiting for it on my inbound (20h now)! Of course the one time I do not have insurance it is delayed, twice...

Isn't this really typical?