km/h rather than kph. Has to be said that the 5 furlongs per kilometre is a new conversion to me but seems wonderfully accurate. I make 5 furlongs = 1006m so that's 99.5% accuracy -- good going by any standards!
One thing I think metric captures better than imperial, though, is scale. once you have learned the meanings of kilo, nano, deci, milli, micro, Mega, Giga, etc., then you have to learn only what a metre, or gramme, or litre, or whatever is and you have virtually all scales of all measurements covered. By contrast each new scale in Imperial is given a different name so you have to learn the relationships separately -- and even then the numbers themselves don't lend themselves to easier visualisation, I think. A yard is to a foot as 3/8 of a mile is to a furlong, and a stone is to a pound as 14/16 pound is to an ounce...
But kilo is to mega as mega is to giga, is to Tera... simpler scaling. For the win.
I still enjoy being able to use and think in and convert between both systems. This has the advantage that I can talk to my grandma and describe something being so many metres long and then convert to yards for her benefit -- or from grams to ounces and pounds whenever my mum needs help with reading a recipe. But I know which system I prefer to think in!