Hi guys.. My dad's birthday is on next month. I am thinking to give a him a useful gift. He is a dry wall worker. While searching for something that helps in his work, I have seen the drywall axe http://www.sparkinnovations.com/project/drywall-axe/, a product of Spark innovations. Does anyone here used it? How much useful is it? What is the usual price of a drywall axe? Are there any specifications, we have to look for while buying it?