The pros and cons of crank self-extractors I'd like to know more about the reliability of self-extracting crank bolts, but haven't found much information on how they perform (or how they don't). 



My interest stems from touring and international travel, but also from practicality. It seems like a no-brainer to be able to remove your crankarms with a common allen key without having to carry around a separate crank puller (or using riskier emergency removal methods). 

Beyond concerns of not being able to remove the extractors themselves (for lack of a pin-spanner), I'd like to know whether these have a history of characteristic failure. I haven't found anything in the way of recommending them or condemning them.

I know that FSA, Sugino, and TA manufacture these gadgets, but are they as good on a bike as they are on paper? Are they simply unnecessary?
I have them on my Ultegra equipped nine speed bike and love them. They are especially nice when cleaning up the bottom bracket and crank/chainrings. Just a couple of quick turns with an allen key and off the the crank arm comes and goes directly into the cleaner. I wipe down the bottom bracket area and reattach the crank arm and it's ready to go. Easy peasy, takes maybe ten minutes if that.