As a cashier, I prefer to use speed IDs when I have long shifts (more than 4 hours). I personally find it easier to just scan the slip rather than type in my numbers/PIN every time I switch a lane, which happens surprisingly often. I never leave them lying about and always take the slip with me for breaks & lunches and discard it once shift is done.
I did the same thing when I was a cashier. I would also write my break times on it so I would remember when to go. I never use them when I back-up cash.
TIP: If you enter in the time that your shift ends, the speed ID can't be used after that time. So if someone garbage-picks your speed ID to try and frame you, they can't use it because it's expired.
If I were a GSA or someone else with supervisor status, I probably wouldn't use speed IDs.
I heard once that using a speed ID as a "Supervisor" still requires you to enter your PIN. Is this true?