A friend of mine claims Fahrenheit is more convenient because of "-ties". "Today it will be in the fifties/sixties/thirties/high seventies." Celsius doesn't have conveniently-spoken ranges that give users a general idea of the weather. I countered with high and low teens, low twenties, but I don't think his point is completely invalid.

You say centimeters are better for small things and meters better for large things, but neither are very useful for things that might constitute an arm-load. I'm not sure that sentence is very clear, so I'll try examples. My laptop is 36 centimeters wide, which is an inconveniently large number of units for it to be, but it's only a little more than a foot. This textbook: about a foot square. That hard-drive is half a foot (I'll admit that "six inches" was easier to the tongue, but in reality it's closer to seven, which I wouldn't say). What I'm trying to say is that the unit "foot" is very convenient for things that we might be handling in everyday situations, unless those things are hand-sized.