I've heard talk that people are generally fed a LOT of misinformation about condoms, not just lying about the statistics of their efficacy, but about the overall experience of protected sex. From what I've heard, it seems that people are under the (likely mistaken) impression that protected sex is without significant sensation, and is thus very dull.
Personally, well...I'd use a condom every single time, unless I was sure that both the missus (figure of speech, not implication of actual marriage) and I were both clean of any STDs and were totally unable to sire/bear children. If neither of those conditions are met, I'm wearing a rubber come hell or high water.