Just a quick acknowledgement of the Logitech M570 Wireless trackball.....
This trackball is the best so far from the trackman series of trackball inputs, its two extra programmable buttons are indispensable inside SolidWorks.
Paired with any 3DConnexion device the sky's the limit.
In my case I have a SpaceNavigator and the M570 with the M570's golbal button 4 assigned to keystroke "y" and global button 5 assigned to keystroke "n".
This lets me answer yes or no to several if not all dialog boxes with a Yes or No choice.
The Limits are endless because on both devices the buttons can be programmed for independent software packages. (i.e. inside SW the buttons are assigned to
"m" for measure on the fly and "space" for view orientation.)
From the trenches,