We use litres for most liquid things, save for large volumes of water in reservoirs, say - for that we use cubic metres. And for crude oil we use "barrels", although I have no idea what that is, to be honest - but I used to hear it on the news.
In fact most of the measurements in the metric system get used very rarely; for instance, for distances we normally use only metres and kilometres, not decametres and hectometres, etc. The last time I used those were in school, learning to make conversions.
It's easy because you just add or substract zeros.
I find centimetres and millimetres handy for measuring small things - I can more or less grasp feet and inches, but I get lost when people start talking about eighths of inches.
As for Fahrenheit - I know that I like temperatures in the seventies and that's about it!
I was glad when they started using Celsius in the UK.
Although by law the UK is now supposed to be metric, and in fact it's so since the seventies, when they started by decimalising the pound, most things come labelled in imperial and metric, and things like milk come still in pint and multiples of pint bottles - for instance, a 2 pint bottle, with a label saying "1.136 litres". Btw, a UK pint is larger than a US pint.
As for our relative heights: yes, you're practically 180cm tall, or 1m 80cm, so yes, you're 17cm, or 6.69in taller than me. I'm average height for a Spaniard, but as Erunáme can tell you, really pocket-sized.