It is a good brush. Though a lot of cheaper options are also available. But if you have a good cycle you should have good cleaning tools
I got a new 105 cassette and chain as my old one was wearing off. This was a good buy to clean the entire thing, as I realized that not maintaining the previous one was one of the reasons for it wearing off quickly.
Nice Chain & Drivetrain Cleaning Brush
Recommended to buy, could have been more robust, but gets the job done.
The claw part of the Muc-Off Claw Brush works fine to get at grime in the gears. The various brushes part of the Claw are, however, a little insubstantial. And the entire tool has a somewhat insubstantial feel to it. Maybe there is no alternative, given that the Claw needs to fit in a fairly narrow space?