Describe the ultimate rappel safety

[fuzzy-hair-man]

Something like the Petzl ASAP seems a good rappel safety to me.

AFAIK it's self minding you can tow it up or down the rope without any manual intervention from the user, it shock absorbs shock loads it appears relatively quick to get on and off rope.

CONS:
toothed safety so there is the possibility of a damaged rope although the clutch system which limits shock loads should prevent this.
Fall distance might be higher than otherwise (safety is not much use if you hit the ground anyway)
Complex and probably vulnerable to mud, sticks etc, not designed for the cave environment.
Probably weights a bit much at 427 grams.
Only works on 10.5-13mm rope.
Might be a pain if your used to rappeling quickly (perhaps an adjustable speed)

But a lighter, cave proof ASAP which is useable on down to 9mm rope would be the rappel safety I'd be most likely to use.

It would be kind of cool if you could lock it so that you could use it as an ascender on the way up (without pulling down sharply).

Note: The ASAP is designed for industrial use with twin ropes.

[cave rat]

Well, I use the French Wrap. Light weight and inexpensive. A 8MM Pursik line is all you need.

I use about 4 - 5 wraps, depending on the type of rope I am using. It has worked great for me so far and anyone can use it for different types of descending device, if trained right.