For some people it simply does not help with the workflow. For me it is a significant upgrade as it allows me to never use the normal mouse to move around in 3D, and allows me to quickly move the view to where I want it to be. Without it, moving in 3D just feels clunky to me.

But as I said, it is a preference.

I really got used to a space mouse with a piece of software called Geomagic Wrap, which we were using to take point clouds from a 3D scanner and turn them into solid models. Part of that process involves turning the model every which way to look for holes and whatnot in it to correct, and being able to use both hands for this really sped up the process. At this point I just cannot stand doing the Click-a click-a click-a click-a required to move a model around with the mouse. And if I'm modeling something large like a building or a landscape in a video game? Forget it. I want to be able to fly the camera around.

I don't have as many hours in SolidWorks but for me, trying to navigate without a 3d mouse feels like riding a bike with square tires. I could manage to do it but why. At the end of the day though it's a preference. Likewise I have to murder the x and y axis on it for things to click in my head, which is another preference. I suppose growing up as a gamer may have something to do with that. I don't want to move/rotate the object, I want to move/rotate the camera..