I think marianned's concern about the cost of care as we age is a valid one, and one I don't think the author addresses as much as he may have. The people he spoke with largely had options. What do older people in poor health with no money do? I think their only option may be lower quality nursing home. That's one of the things I fear.
I don't think I'm that concerned about pain, because hospice seems to have gotten a good handle on pain management.
I do worry about physical failings - losing my mobility, eyesight... and especially my hearing! Funny, I think I'm in the minority when I say I'd rather lost my eyesight than my hearing.