It was very picky about recognizing the print. This could be good or bad, but was generally frustrating. It caused some programs to work very poorly or not at all. It ran along with every program (it wasn't just for logging in, but for logging in to other programs that require passwords as well) and if it didn't work, it sometimes wouldn't allow you to manually enter a password either. The database of password/print wasn't stored locally (bad implementation) and would fail to connect pretty regularly. It didn't handle password changes very eloquently, which would lead to getting locked out.

Did I mention this technology is evil? Do you own the data that represents your fingerprint once your employer has it? Is that information protected? When you leave do they get rid of it, including backups? If it isn't stored locally (or even if it is) is it encrypted in transit? Would that data be protected in the case of a crime or other legal reason where authorities might ask for it?

Bad matching algorightm, slow, and crashing windows (or specific programs) are all pretty accurate besides the things I mentioned above.