In reply to Joel Perkin:
It is an intrinsically safe option as a means of auto-locking a Munter¡¦s. So there is no reason why it cannot be used, providing it is used correctly. However, I class it as a ¡¥something I have in my bag¡¦ if the situation arises. Before I would resort to that I would have had have dropped my belay device (guide), and been in the position of doubting my ability to use a normal Munter¡¦s (can¡¦t see actually when that would happen though), and being able to tie it off correctly when I need to.