It all depends on what you're training for - a lot of the items are mostly fun gadgets, but will definately help improve your grip strength/hand health. I say they're gadgets because you don't need those specific items to develop strong healthy hands, but they sure are fun.
I've used the bomb. It's tough, especially if you use it to play catch.
John's also a great guy, customer service is excellent. Side note, he hit 1105lbs (new record) on the silver dollar deadlift on the 14th on a busted bar.