As someone whose day job is working 12 hour shifts in an emergency room and who is constantly confronted by just how delicately mortal we all are, I have to confess a certain fondness for writers whose characters who don't drop off the twig at any given moment.

I agree that it is an overdone plot device in SF/fantasy, but in my mind it can be and often is done right, or at least in a semi-plausible way (authors: please keep in mind that there are people out there like me who will know when you don't have a clue about basic 1. medicine, 2. human physiology, 3. physics). As a reader, I appreciate an author who fully understands the impact of death and does not squander characters--or the reader's emotional attachment to them.