Weird, I find height much easier to remember in the metric system - everyone's a meter something (unless you're a kid, or as tall as Glenn Jacobs), like "meter *sixty five*", so you just remember the last two numbers. With feet and inches you have as much cognitive information ("*five* foot *five*"), or more because the number of inches is base 12 instead of base 10, but almost 1/3rd the accuracy!

And doing relative calculations (ex "10% longer than 5'11") requires extra steps (1.1 * (5 * 12 + 11), and then convert to feet and inches again), while with metric anyone can do it in his head on the fly! Even typing "5 ft 11 in" into Google is a pain in the ass compared to "180 cm", and I still can't figure out how to get it to produce output in both feet and inches!