What is the warranty on the lock? You will find that the higher the warranty, often the better the lock is. Those that only include a short warranty may not be as dependable when it comes to the long haul of your lock.
Consider the residential security grade of the lock. You will find that there is a grading system, much like when you were in school. A C is good, but a B is better, while an A is the best. You will find that some locks get a triple A which puts it as the best of the best.