Great tool to track progress and consistency. As mentioned, accuracy can be thrown off but only on wild pitches, so not really a problem. Also, it would be considered a "slow" gun as it measures speed at the catcher's end. (Ball is fastest at the point of release, so guns aimed close to the pitcher are considered "fast" guns)
Pros: Relatively inexpensive, durable, long battery life (going on 3rd season)
Cons: accuracy can be thrown off if catcher has to move glove quickly.
You have to be in the line of fire!
Bottom Line: I would recommend to a friend