Anything metric > anything imperial

km/s

At least is not mph, that shit makes no sense.

Us joggers using min/km

That's good and all. But we should go deeper.

For instance, what's the conversion factor to planck lengths per unperturbed ground-state hyperfine transition of the caesium 133 atom (second) or maybe even per Planck time unit?

m/s is the best, everyone know aprox. what is an meter and an second to know the velocity, but not so easy with km and a hour.. 50km/h seems slow, but not so 13 m/s.

Hotter take: pronounce it KILL-o-meters and not kill-AH-meters.

Why not just go with the universal and unitless proportion of "c"?

Or, for your slowpokes, parts per million or billion of "c".

Miles "Tails" Persecond