For awhile they were my primary card, since we were going for a Concorde award. But they COMPLETELY screwed us up at tax time. My Diners and Citbank Visa sent stuff in late January or early February, but First USA didn't send the year-end statement until April. Big help, that.

After that, I began using them for overseas only -- a fair amount of our purchases abroad are deductible, but at least if I save statements from trips abroad, I don't have to separate out other, non-travel-related stuff. This is the last straw,though; I think I'll accumulate all my BA miles from now on on Diners.