My wife LOVES the fingerprint security. Only one swipe and she's in, rather than having to enter the 4 digits.

I think you can have up to 5 fingerprints.

If you are thinking about that article about how the fingerprint sensor was defeated, don't worry about that. The media overhyped it:
http://www.macrumors.com/2013/09/24/touch-id-bypass-detailed-average-consumer-shouldnt-worry/

Quote:
Rogers goes on to explain the process, which requires an unsmudged, complete print of the correct finger and a way to “lift” the print using cyanoacrylate (super glue) fumes, fingerprint powder, and fingerprint tape. The lifted fingerprint must then be photographed, edited, and printed onto transparency film, where it is converted to a usable fingerprint via a PCB board or a laser printer.