Yes it's worth it. You probably won't need to use it. BUT it's great for quick and easy clearing of jams if you get a bad ball, and can be a game saver if your batteries die in a game so you can still shoot.
Had a nasty experience on the X-ball field at Amsterdam, one dead Halo, was feeding balls in 4 at a time. Shot 2 people for definate with a possiblity of a third. Had I had 7 balls at a time we obviously would have won and made the finals