I thought it was **** too, before I really used it properly.
The Momentus strength is a good club. It's short, so you can swing indoors, no problem.
I don't make full swings with it, although some people do. It's great for practicing the address position. The club is heavy enough that you really don't get lazy about the original shaft plane angle. You really think about it when you make your address with this club. And you use this feeling when you go back to your normal clubs.
2. on the backswing it's easy to stay on plane with this. Just like the drill where you hold a medicine ball and do your swing, you won't bring this inside or outside on the backswing, b/c it will feel like you are holding it inefficiently.
3. It helps you make a consistent top of the backswing. it's heavy, so you definitely complete the shoulder turn, and you won't "lift your arms" or cross the line at the top. As you know, most people go further at the top of the backswing position than they think. But this stops that.
The list goes on.
It's an EXCELLENT tool, but really it's about how much money you're willing to spend. Some people buy every tool out there. And this one costs $99. That's too much for a lot of people to spend on a training aid when there's so many to choose from.