Mitigated
On the whole, it's a good idea.
The ergonomics are correct but the whole thing looks a bit cheap.
But the ball is not heavy enough so it lacks inertia. There are frequent disconnections that force to turn off and on the trackball frequently. The sensitivity settings are useless because at the very least it's already a bit too sensitive to be accurate. So beyond that it's useless.
I'm thinking of changing to something more serious.