[asid61]

We used one last year on our elevator (thanks 2363!) too prevent backdriving. This let us run a 24in/sec elevator with two RS775-18v without overheating issues, although we did lose some gears on the Versaplanetary dual input later in the year.
We also used one this year to hold our angler in place, but there were many issues with it that caused it to be ineffective. It may have just been the brake we used or manufacturing tolerances.