I purchased the Pop's Gripper and CrushBooster about 1-1/2 years ago when they were first being sold, after seeing the Product Reviews by Mighty Joe and Jedd Johnson. Without question this is the best Grip Machine on the market, regardless of price. In particular I like the bands, the wider grip bars and the extra wide base on the Grip Machine. Almost all other Grip Machine have a very narrow base which appear to be very unstable - and look like they would fall over if pushed a little bit. I like the use of the bands, as well as hanging weights (and sometimes using both at the same time) from the CrushBooster.
I would like to suggest one small adjustment to the CrushBooster. The handle on the bottom, or pull up bar, of the CrushBooster needs to be extended about 5". Use of heavier weight or heavy bands makes this bar very difficult to lift up for negative holds. I just welded a 5" bar extension on the end of this bar and everything now works great.