Never had an issue, they are "good to the last drop."

The Nikon algorithm always seems to keep on the conservative side of the number of shots remaining so you always get more shots than it shows and it never surprises you by suddenly not being able to save a shot. If it shows space for 10 more shots and you fire off a burst of 10 they will fit just fine in my experience.

OTOH, as Perrone advises, better to switch cards well before you have to. It's not like you are "wasting expensive film" by not filling the card, and there is nothing more frustrating than watching great moments happen while you are reloading.

tim