What are BTC ATMs and how to use them

https://99bitcoins.com/bitcoin/atm/

This is a nice beginners guide to read.
I have seen one once before where I live but I feel the fees over 15% and higher throws someone off I feel that this would be for an emergency situation to buy BTC quick or someone that isn't very computer literate and they were advised to use that ATM to buy some crypto as an investment.
I was wondering if anyone here has ever bought BTC using one of these machines and was it user friendly and how quick did it really take to receive your funds into your wallet from the time you purchased using this machine.