My (paper) note book (a cheap $0.50 mead spiral bound model) can be thrown in my bag without any concern over it being damaged, or remembering to charge it, and it will remain functional. It has no obvious value to thieves, and leaving it lay visible in the car does not appreciably increase my risk of the car being broken into. It is also lighter, and quicker to use than any tablet I've used.
Given the spat of hard disk failures I've experienced in the last few months, I actually trust the paper copy to remain useable longer. Also, the lower data density of a paper note book helps mitigate the risk as well - damage to a notebook simply doesn't affect the quantity of data that the loss of a hard disk, tablet, or flash drive can affect.
